SAN JOSE, Calif. -- Sean Miller knows what it feels like to take Xavier to the Elite Eight. Now he knows the bitter feeling of being on the other side.
Musketeers guard Trevon Bluiett scored 25 points and fed center Sean O'Mara for the game-winning layup with 44 seconds remaining as 11th-seeded Xavier upset second-seeded Arizona 73-71 in the NCAA Tournament West Region semifinals at SAP Center on Thursday.
Xavier will make its third trip to the Elite Eight, the first since Miller coached the 2008 Musketeers there before leaving for the job in Arizona that offseason.
The Musketeers (24-13) will oppose top-seeded Gonzaga (35-1) on Saturday, with the winner earning its first trip to the Final Four.
"I cannot say enough good things about Xavier," Miller said. "It's not because I used to be there. I think their coach (Chris Mack) is awesome. He had his way with us tonight. He got his players some great shots. I knew going into the game it was going to be a challenge."
Xavier scored the final nine points, five by Malcolm Bernard.
The play for O'Mara was run quickly so as to give the Musketeers another possession if one proved necessary.
Arizona guard Allonzo Trier scored 15 of his 19 points in the second half, but his 3-pointer from the key with five seconds remaining bounced off, and Xavier got the rebound and ran out the clock.
The Wildcats (32-5) took a 71-64 lead on Kadeem Allen's driving layup with 2:52 remaining but missed their last six field-goal attempts as Xavier made a run.
Bernard made a 3-pointer from the left baseline and two free throws on a second-chance possession to allow Xavier to creep close. Bluiett tied the game on two free throws with 1:54 left after being fouled on a rebound following a missed Arizona shot.
Bernard scored 15 points and J.P. Macura added 14 for Musketeers, the lowest remaining seed in the tournament.
"We weren't perfect in the second half, but we were in the last three or four minutes of the game, and that's the reason we were able to win," said Mack, who was an assistant on Miller's staff in 2008 and has been the coach since.
Xavier avenged a 68-60 loss to Arizona in the 2015 Sweet 16 in Los Angeles.
"It feels good," said Bluiett, the only returning starter on either team from that game. "For one, just to be able to get that revenge we've been looking for. And two, just to make it to the Elite Eight. It's been a while since the program has done it. Just to get back there is a surreal feeling."
Center Dusan Ristic scored 17 points for Arizona, which had won six in a row and 11 of 12.
Xavier shot 52.8 percent. Blueitt made 9 of 17 shots and Bernard 5 of 6.
"We could not guard them," Miller said. "It wasn't the total points. It was the field-goal percentage. The 3-point percentage. Very few times, if we're up by eight points with under few minutes (to go), do we lose. But we did."
Arizona shot 43.5 percent and had a 35-27 rebounding edge.
Wildcats freshman forward Lauri Markkanen, averaging 15.8 points a game, scored nine points on 3-of-9 shooting and grabbed eight rebounds.
Arizona scored 10 of the first 12 points despite Allen drawing two personal fouls.
Xavier slowly crept back into the game behind Bluiett and Macura, who scored 15 of the Musketeers' final 17 points of the half. Bluiett assisted on the other basket.
"I'm extremely happy on how we played together today," Macura said.
Guard Rawle Alkins hit a 17-footer as time expired in the half to give the Wildcats a 37-35 lead.
Alkins sustained a fractured right index finger early in Arizona's win over Saint Mary's in the second round of the NCAA Tournament on Saturday. He scored four points in 31 minutes Thursday.
NOTES: Arizona coach Sean Miller missed out on the chance to earn another $175,000 this weekend on top of his $2.5 million guaranteed compensation. The bonus would have kicked in if the Wildcats had reached the Final Four. He earned $50,000 for reaching the Sweet 16. ... Xavierand Arizona are two of nine schools that have reached the Sweet 16 six times since 2008. ...Xavier sophomore G Edmond Sumner was averaging 15 points and 5.0 assists before sustaining a season-ending knee injury Jan. 29. The Musketeers were 15-6 in his 21 games.