Important bouts in the career of former heavyweight champion Muhammad Ali:
* Sept. 5, 1960 - Wins the Olympic light-heavyweight gold medal in Rome in a unanimous decision over Zbigniew Pietrzykowski of Poland.
* Oct. 29, 1960 - Makes his professional debut in his hometown of Louisville, Kentucky, winning a six-round unanimous decision over Tunney Hunsaker, whose day job was police chief of Fayetteville, West Virginia.
* Feb. 25, 1964 - Boasting a 19-0 record, wins the heavyweight title at age 22 by beating Sonny Liston, who surrenders after six rounds, in Miami Beach.
* March 22, 1967 - After eight successful title defenses, including another win over Liston and one over former champ Floyd Patterson, Ali knocks out Zora Folley in the seventh round in New York. It was his last fight before losing his titles and facing prison for refusing to be inducted into the U.S. Army.
* Oct. 26, 1970 - After a 3 1/2-year layoff due to his legal troubles, Ali returns to the ring in Atlanta against Jerry Quarry and wins by TKO in the third round.
* March 8, 1971 - Ali faces Joe Frazier, who had become heavyweight champ during Ali's hiatus, in a greatly anticipated match that promoters called "the fight of the century" in New York. Both men were undefeated going into the bout, which pitted Ali's speed and reach against Frazier's doggedness and stronger punching power. Ali started strong but Frazier dominated the latter part of the 15-round fight and won by unanimous decision.
* March 31, 1973 - Ali's second loss is a split decision against Ken Norton, who broke Ali's jaw. Six months later Ali wins a rematch with Norton.
* Jan. 28, 1974 - Ali beats Frazier, who had lost his title to George Foreman, by unanimous decision.
* Oct. 30, 1974 - Ali is a decided underdog going into the "Rumble in the Jungle" in Kinshasa, Zaire, against the fearsome and younger Foreman. Instead of his usual dancing footwork, Ali spends much of the fight covering his face with his arms and leaning against the ropes in a strategy called the "rope-a-dope." His plan is to let Foreman tire himself out by throwing punches that did no serious damage and it works, allowing Ali to knock him out in the eighth round and reclaim the major boxing championships.
* Oct. 1, 1975 - The second rematch with Frazier is called the "Thrilla in Manila" and part of the pre-fight hype includes Ali calling Frazier a gorilla. Ali wins when Frazier is unable to come out for the 15th and final round. The temperature approached 100 degrees (38 C) and Ali describes the fight as the closest he had come to death.
* Feb. 15, 1978 - Ali, now 36, loses his titles by split decision to Leon Spinks, 25, who had only seven professional fights after winning a gold medal in the 1976 Olympics.
* Sept. 15, 1978 - Ali gets the a heavyweight title back by beating Spinks in a 15-round unanimous decision, making him the first man to reign as champion three times. He then retires.
* Oct. 2, 1980 - At age 38 he attempts a comeback in a title fight against Larry Holmes, a former Ali sparring partner, but his skills are clearly eroded. Ali's trainer stops the fight after 10 rounds, marking the only time in his career that Ali lost by anything other than a decision.
* Dec. 11, 1981 - Ali's final fight is a unanimous decision loss to Trevor Berbick.
CELEBRATE MUHAMMAD ALI THROUGH THE YEARS:
Muhammad Ali through the years
Key fights in the boxing career of Muhammad Ali
Eighty-five pound Cassius Marcellus Clay, Jr., is shown posing at twelve, prior to his amateur ring debut in 1954, a three minute, three round split decision over another novice named Ronnie O'Keefe, in Louisville, Kentucky. (AP Photo)
Muhammad Ali (Cassius Clay) of Louisville, Ky., member of the West team in Golden Gloves action in New York on March 21, 1960, leads with a right against Gary Jawish of Chevy Chase, Md., in their heavyweight championship bout. Ali won by TKO in the third round. (AP Photo/John Lent)
Cassius Clay, 18-year-old from Louisville, Ky., throws a right at Tony Madigan of Australia, left, during the light heavyweight boxing semi-finals at the Summer Olympic Games in Rome, Italy, Sept. 3, 1960. Clay won the bout with all five votes of the judges. (AP Photo)
A trio of U.S. boxers wear gold medals at the Olympic village in Rome, Sept. 6, 1960. From the left are: Wilbert McClure of Toledo, Ohio, light middleweight; Cassius Clay of Louisville, Kentucky, light heavyweight; and Edward Crook of Fort Campbell, Kentucky, middleweight. (AP Photo)
19-year old Cassius Clay, last year's Olympic gold medalist who recently turned professional, connects with a straight right to the jaw of Kolo (Duke) Sabedong during a 10-round heavyweight bout in Las Vegas, Nevada June 26, 1961. Clay, who maintains he will be world champion before he turns 21, scored a unanimous decision, to run his professional winning streak to seven straight. Clay, of Louisville, Ky., weighed in at 197 1/2 lbs., while Sabedong, of San Francisco, Calif., tipped the scales at 226. (AP Photo)
Young heavyweight fighter Cassius Clay is seen at City Parks Gym in New York, Feb. 8, 1962. (AP Photo/Dan Grossi)
Muhammad Ali (Cassius Clay) (right) lands on Don Warner's jaw in an early exchange of their fight in Miami Beach, Fla., February 28, 1962 with a straight right. It was the same punch which knocked Warner through the ropes in Round 4 and headed him for a technical knockout as the fight was stopped soon after he climbed back to the canvas. (AP Photo)
FILE - In this Nov. 15, 1962, file photo, young heavyweight boxer Cassius Clay, who later changed his name to Muhammad Ali, points to a sign he wrote on a chalk board in his dressing room before his fight against Archie Moore in Los Angeles, predicting he'd knock Moore out in the fourth round, which he went on to do. The sign also predicts Clay will be the next champ via a knockout over Sonny Liston in eight rounds. He did it in seven rounds. Ali turns 70 on Jan. 17, 2012. (AP Photo/Harold P. Matosian, File)
Young boxer Cassius Clay is seen with his mother, Odessa Grady Clay, April 2, 1963, at an unknown location. (AP Photo)
Cassius Clay, young heavyweight fighter, thrusts his fist out, Feb. 19, 1964, as he tells a crowd at Surfside, Fla., how he'll hit champion Sonny Liston in their upcoming bout at Miami Beach. Clay and his followers paid an unexpected visit to Liston's Surfside camp. (AP Photo/Harry Harris)
Sonny Liston, right, lowers his head and works in close during 6th round of heavyweight championship fight with Muhammad Ali (Cassius Clay) in Miami Beach, Fla. on Feb. 25, 1964. Liston suffered a cut left eye and a strained left shoulder before the fight was stopped at the end of the round. (AP Photo)
American boxer and sometime actor Muhammad Ali (then Cassius Clay) as Eric Sevareid interviews him during an episode of the CBS Evening News, New York, March 24, 1964. (Photo by CBS Photo Archive/Getty Images)
World heavyweight champion Muhammad Ali is held back by referee Joe Walcott after Ali knocked out challenger Sonny Liston in 1 minute, 42 seconds of the first round of the scheduled 15 round championship bout in Lewiston, Maine, May 25, 1965. (AP Photo/stf)
Muhammad Ali reacts after the referee stopped the bout between Ali and European champ Karl Mildenberger, Sept 10, 1966, in Frankfurt, Germany. Ali won by technical knockout. (AP Photo)
Muhammad Ali lands with a left to the head of Ernie Terrell in the seventh round of their 15-round heavyweight championship fight in Houston, Tex., Feb. 6, 1967. Ali battered Terrell throughout the entire fight to win by a unanimous decision. (AP Photo)
Former heavyweight boxing champion Muhammad Ali sits in the back seat of a limousine with his wife Belinda after he was released from Dade County jail in Miami, Dec. 23, 1968. Ali served 8 days of a 10-day sentence on a 1967 traffic charge. He was among 50 prisoners released early on Christmas amnesty. (AP Photo/Harold Valentine)
Muhammad Ali delivers a hard right to Jerry Quarry on October 26, 1970 in a scheduled 15 round fight at Atlanta, Ga. Ali was declared the winner after Quarry didn't answer the bell for the fourth round. Quarry had a gash over his left eye that required 11stitches to close. (AP Photo/Joe Holloway Jr.)
Muhammad Ali holds his 2 year old daughter, Maryum Ali, while waiting to tape a show for ABC "Wide World of Sports" in New York on Oct. 29, 1970. With the fighter is his wife, Belinda. (AP Photo/ Anthony Camerano)
Muhammad Ali has his right cocked as he punishes the heavy bag with lightning-quick lefts during training in Miami Beach, Fla, on Monday March 4, 1971 for his heavyweight title fight with champion Joe Frazier in New York. (AP Photo)
Muhammad Ali lands a blow to the face of Jimmy Ellis in the 11th round of their 12-round heavyweight fight in Houston on July 26, 1971. Ali landed blows freely in the 11th round and the fight was halted in the 12th round with Ali getting a TKO. (AP Photo)
FILE--Muhammad Ali lies on canvas after being knocked down by heavyweight champion Joe Frazier in this March 8, 1971 file photo. The heavyweight championship fight between Frazier and Ali was billed as The Fight, and 25 years later, it still is The Fight, secure in its place in boxing legend. (AP Photo/File)
Former heavyweight champion Muhammad Ali tells European heavyweight champ Joe Bugner, seen Dec. 18, 1972, that he will stop him in seven rounds in their 12-round match in Las Vegas on Feb. 14. (AP Photo)
Muhammad Ali, right, winces as Ken Norton hits him with a left to the head in their scheduled 12-round re-match, Sept. 10, 1973 at the Forum in Inglewood, California. (AP Photo)
Muhammad Ali, left, and Joe Frazier in the 12 round non-title fight that took place at Madison Square Garden in New York, January 28, 1974. (AP Photo)
FILE - In this Oct. 30, 1974 file photo, Challenger Muhammad Ali watches as defending world champion George Foreman goes down to the canvas in the eighth round of their WBA/WBC championship match in Kinshasa, Zaire, on Oct. 30, 1974. Foreman was counted out by the referee and Ali regained the world heavyweight crown by knockout in the bout dubbed "Rumble in the Jungle." (AP Photo/File)
**FILE** Spray flies from the head of challenger Joe Frazier, left, as heavyweight champion Muhammad Ali connects with a right in the ninth round of their title fight in Manila, Philippines, Oct. 1, 1975. Ali won the fight on a decision to retain the title. (AP Photo/Mitsunori Chigita, File)
Heavyweight champion Muhammad Ali gets in a little road work escorted by two automobiles and a police cruiser in a park in Greenbelt, Maryland, April 28, 1976. He will fight challenger Jimmy Young in a championship bout on Friday. (AP Photo/Bob Daugherty)
World heavyweight boxing champion Muhammad Ali waves with his fists behind the balance during weigh-in ceremony on May 23, 1976 in Munich for his upcoming title fight against British champion Richard Dunn on May 24, 1976 in Munich?s Olympic hall. (AP Photo)
Heavyweight champion Muhammad Ali knocks challenger Ken Norton back with a right hand punch in the 14th round of their title fight Tuesday night, September 28, 1976. Ali retained his title with a decision win in the 15-round fight in New York's Yankee Stadium. (AP Photo)
Heavyweight champ Muhammad Ali prepares his right as he jabs at challenger Leon Spinks with his left during the first round at their 15-round title bout at the Hilton Pavillion in Las Vegas, Nev., Feb. 16, 1978. (AP Photo)
Muhammad Ali, noted mouthpiece of the boxing world, has to listen here as heavyweight champion Leon Spinks has the floor for a word during their contract signing in New Orleans, April 11, 1978. The fighters will meet on September 15 in the Superdome. (AP Photo)
Former heavyweight champ Muhammad Ali, right, trades punches with a Soviet boxer in one of three two-round unscored exhibition bouts on Tuesday, June 20, 1978 in Moscow. Afterwards, Ali said he thought that he had lost one of the bouts, and added on an uncharacteristic modest note: ?Me, I?m finished. My day is over. I?m going on guts and courage and native ability.? (AP Photo/Yurchenko)
Muhammad Ali ponders a question at news conference following his WBA heavyweight title bout with Leon Spinks in New Orleans on Friday, Sept. 16, 1978. Ali regained his title with a 15-round unanimous decision. ?Thank God it?s over,? said Ali. (AP Photo)
LAS VEGAS - OCTOBER 2,1980: Muhammad Ali (L) throws a punch against Larry Holmes during the fight at Caesars Palace, on October 2,1980 in Las Vegas, Nevada. Larry Holmes won the WBC heavyweight title by a RTD 10.
(Photo by: The Ring Magazine/Getty Images)
Trevor Berbick, left, and Muhammad Ali seem to have an equal reach as they slug it out during a Friday night boxing match on Dec. 12, 1981 in Nassau, Bahamas. Berbick won the 10 round bout with a unanimous decision. (AP Photo)
JUL 14 1981; Ali, Muhammad (Boxer) - Ind.; (Photo By Lyn Alweis/The Denver Post via Getty Images)
Former heavyweight champion Muhammad Ali, clowns around as he takes a "punch" to the nose by the Rocky Marciano award during a photo session at the Downtown Athletic Club in New York, Nov. 19, 1984. The award was presented to Ali during the organization's annual Salute to Boxing Greats. (AP Photo/Marty Lederhandler)
Muhammad Ali watches as the flame climbs up to the Olympic torch during the opening ceremonies of the Summer Olympics Friday, July 19, 1996, in Atlanta. (AP Photo/Doug Mills)
Muhammad Ali poses with Dream Team members from left: Scottie Pippen, Hakeem Olajuwon, Reggie Miller, Shaquille O'Neal, Karl Malone and Gary Payton after receiving the gold medal, which replaces the 1960 gold medal he lost, during half time ceremonies at the gold medal game of basketball competition at the Centennial Summer Olympic Games in Atlanta Saturday, August 3, 1996. IOC president Juan Antonio Samaranch presented the medal to Ali. (AP Photo/Eric Draper)
Muhammad Ali playfully spars with a photographer while on a tour bus to visit Alain Leroy Locke High School, Tuesday, December 3, 1996, in South-Central Los Angeles. Ali visited two high schools and the Watts Labor Community Action Committee to promote his new book, "HEALING: A Journal of Tolerance and Understanding," with co-author Thomas Hauser. (AP Photo/Nick Ut)
Muhammad Ali, known as "The Greatest," poses next to a Wheaties "The Breakfast of Champions" poster during the unveiling of the 75th Anniversary cereal box in his honor in New York, Thursday Feb. 4, 1999. "Muhammad Ali is quite possibly the most recognized sports figure of our time," said Wheaties market manager Jim Murphy. "That's why we are especially proud to recognize him on our box during our 75th anniversary celebration." (AP Photo/Bebeto Matthews)
Johnny Grant, right, honorary mayor of Hollywood, reaches over to shake the hand of Muhammad Ali after the boxing legend's star on the Hollywood Walk of Fame was unveiled Friday, Jan. 11, 2002, in Los Angeles' Hollywood district. (AP Photo/Nick Ut)
Actor Will Smith applauds as he presents the humanitarian award to boxing great Muhammad Ali during the 2nd Annual BET Awards Tuesday, June 25, 2002, in Los Angeles. (AP Photo/Chris Pizzello)
Former heavyweight boxing legend Muhammad Ali waves to the crowd below as his daughter IBA super middleweight champion Laila Ali, touches him after they unveiled a new giant three-paneled wallscape in the Harlem neighborhood of New York, Thursday, Feb. 5, 2004. (AP Photo/Ed Bailey)
Muhammad Ali listen to fans as he prepares to promote his latest book "The Soul Of A Butterfly," co-authored with his daughter Hana Ali, in Harlem, New York, Wednesday Dec. 1, 2004. (AP Photo/Bebeto Matthews)
FILE - In this Nov. 9, 2005 file photo, President Bush presents the Presidential Medal of Freedom to boxer Muhammad Ali in the East Room of the White House. He is now so much a part of the nation's social fabric that it's hard to comprehend a time when Ali was more reviled than revered. (AP Photo/Evan Vucci, File)
** FILE ** Golf great Arnold Palmer, left, greets boxing legend Muhammad Ali, center, and Miami Heat's Dwyane Wade, right, prior to the coin toss at the Orange Bowl football game between Wake Forest and Louisville Tuesday, Jan. 2, 2007, in Miami. (AP Photo/Lynne Sladky)
Former boxing heavyweight champion of the world Muhammad Ali watches from the audience during the opening plenary of the Clinton Global Initiative annual meeting Wednesday, Sept 24, 2008 in New York. (AP Photo/Jason DeCrow)
Producer Jerry Weintraub, left, greets Muhammad Ali at the UNICEF Ball honoring Weintraub in Beverly Hills, Calif. on Thursday, Dec. 10, 2009. (AP Photo/Matt Sayles)
Muhammad Ali waves to the crowd during Muhammad Ali Celebrity Fight Night XVII on Saturday March. 19, 2011, in Phoenix. (AP Photo/Darryl Webb)
Retired boxing champion Muhammad Ali, center, is presented with the Liberty Medal by his daughter Laila Ali, right, as his wife Lonnie Ali, left, looks on during a ceremony at the National Constitution Center, Thursday, Sept. 13, 2012, in Philadelphia. The honor is given annually to an individual who displays courage and conviction while striving to secure liberty for people worldwide. His sister-in-law Marilyn Williams is at right. (AP Photo/Matt Rourke)
Former boxing legend Muhammad Ali arrives for the coin toss prior to the start of the Sugar Bowl NCAA college football game between Florida and Louisville on Wednesday, Jan. 2, 2013, in New Orleans. (AP Photo/Dave Martin)