Federer fades in 5-set loss to No. 78 Dimitrov

Just one set away from yet another U.S. Open semifinal berth, 20-time Grand Slam champion Roger Federer suddenly looked human.

With the 38-year-old, five-time Open champion openly struggling with his normally masterful strokes, and departing for a rare medical timeout before the final set, Bulgaria's Grigor Dimitrov surprised the star-studded crowd by rallying to beat the third-seeded Switzerland native 3-6, 6-4, 3-6, 6-4, 6-2 on Tuesday night in New York.

The victory marked a number of firsts for Dimitrov, who entered the tournament ranked 78th in the world on the heels of a severe slump. The 28-year-old was No. 3 in the world a mere two years ago. The upset over the third-seeded Federer was Dimitrov's first win in eight tries against his friend and occasional training partner.

More important, Dimitrov advances to the U.S. Open semifinals for the first time in his career, marking just his third career semifinal berth in a Grand Slam -- having previously reached the final four at Wimbledon in 2014 and at the Australian Open in 2017.

He has never advanced to the final of a major event.

"It's been a while since I played on (center court at Arthur Ashe Stadium), so in the first set I was a little nervous and I was just trying to find my rhythm around the court," Dimitrov said. "He was serving really good, as he did throughout the whole match. The only thing I was telling myself was to stay in the match. I knew physically I was feeling really, really good."

Federer was clearly not feeling his best in the final two sets, which included several unusual forehand errors well offline for the normal steady star. After dropping a grueling fourth set that lasted 55 minutes, Federer -- who has never retired from a match in his illustrious career -- departed for the locker room for a medical timeout before serving to start the fifth set.

Despite the 10-minute break, Federer could not regain his early form, quickly suffering back-to-back service breaks to Dimitrov in falling behind 4-0 in the final set. For the match, Federer had 61 unforced errors compared to 41 for Dimitrov.

"Grigor was able to put me away," Federer said. "I fought with what I had."

Dimitrov said, "He started slowing down a little bit. For sure, in the end, he was not 100 percent of himself."

Federer entered the match 43-1 in his career against players ranked outside the top 50. Meanwhile, Dimitrov began the night 1-10 against top 10-ranked players in Grand Slams until beating Federer.

Dimitrov will next play fifth-seeded Russian Daniil Medvedev, who overcame a right quad injury to beat former champion Stan Wawrinka of Switzerland 7-6 (6), 6-3, 3-6, 6-1 and advance to his first career Grand Slam semifinal.

Medvedev, 23, became the youngest men's semifinalist at Flushing Meadows since Novak Djokovic in 2010, but he had to fight for it after being hobbled very early.

"I had a big pain in my quadriceps, and I thought I wasn't going to be able to continue the match in the first set," Medvedev told ESPN afterward in an on-court interview. "Before the match, I was feeling perfect. But in the first game of the match, I hurt my quadriceps a little bit."

The 23rd-seeded Wawrinka, who won the title in 2016, came from a break down to level the first set at 5-5, then earned a set point on his own serve in the tiebreaker. But Medvedev won the next three points to claim the set.

After Medvedev took the second set, Wawrinka broke early in the third and closed it out on his third set point, fighting off four break points in the process. But Medvedev responded strongly, breaking early in the fourth set and again to lead 5-1 before serving out the match.

"I took a painkiller in the first set, and in the fourth set I started feeling it," Medvedev said.

Now Medvedev must get ready to face Dimitrov.

"I will see (Wednesday) morning how I feel, but I will do my best to be 100 percent for the semis," Medvedev said.