Michael Dixon scored 21 points, including the game-winning layup with 31 seconds left, as No. 4 Missouri beat Texas 67-66 on Monday night.
Ricardo Ratliff and Phil Pressey added 13 points each for Missouri (20-2, 7-2 Big 12).
J'Covan Brown scored 20 for Texas (13-9, 3-6), which lost for the fifth time in six games, all to ranked teams. Two of those defeats were to the Tigers.
Dixon's winning shot came seconds after Brown had given Texas its first lead since the opening minutes.
Freshman Myck Kabongo had a chance to win it in the final seconds for the Longhorns, but he short-armed a baseline jumper and Missouri's Marcus Denmon grabbed the rebound.
Dixon's heroics came after he nearly cost his team the game.
Texas had rallied from 13 down early in the second half to pull to 65-62. Dribbling the ball at midcourt, Dixon was whistled for a flagrant foul when he swung an elbow and hit Julien Lewis in the face. Lewis made both free throws to cut the lead to one and Brown's leaning bank shot put Texas up 66-65.
Dixon then did what Missouri had done all game: He drove at the basket and his high, banking layup over Jaylen Bond dropped in to put Missouri on top.
After working the ball upcourt, Texas tossed the ball around the perimeter but chose to go to Kabongo instead of Brown — their leading scorer who scored 34 points the last time these teams met on Jan. 14 — for the final shot.
Kabongo finished with 10 points and Lewis had 12 for the Longhorns. Texas outrebounded Missouri 38-26, but a ragged offense didn't have an assist on offense in the first half and the Longhorns were just 2 of 12 on 3-pointers.
Missouri seemed to have the game in control when it opened the second half with a flurry. Dixon was the catalyst, making three straight baskets over Brown and Kim English made a 3-pointer to push the Tigers' lead to 36-29.
Brown, who has struggled badly shooting at home, started finding his touch and kept Mizzou from pulling away. Brown and Phil Pressey matched each other's 3s and Brown added a driving layup and a free throw cut the Tigers' lead to 46-43 with just under 11 minutes to play.
The Longhorns trailed 50-48 with a chance tie or take the lead when Pressey picked the ball from Kabongo, who had opted not to shoot an open 3-pointer and then was whistled for a flagrant foul. Pressey made both free throws.
Missouri had another chance to slam the door on Texas but couldn't. Ricardo Ratliff made a tough layup, then finished a three-point play after a steal by English. A 3-pointer by English with 4:43 to play put the Tigers ahead 63-53 before Texas rallied again behind Brown and Kabongo.
The Tigers gave first-year coach Frank Haith a win in his first trip to Austin since his days as Texas assistant from 2002-2004. The Longhorns twice advanced to the NCAA tournament round of 16 and made the Final Four in 2003 in that span and the home crowd gave Haith an enthusiastic round of applause when he was introduced before the game.