Kansas City, Mo Nolan Johnson had an opportunity to force overtime, and he blew it.
He made the most of his second chance, though.
Johnson atoned for a crucial missed free throw by scoring the go-ahead basket, lifting No. 16 Oklahoma to a 67-65 win over Missouri in the quarterfinals of the Big 12 tournament Friday night.
"This is a tough one," Missouri coach Quin Snyder said. "We didn't make plays down the stretch."
The Tigers did make one big play to take a late lead, but couldn't make another to keep it.
Justin Gage's basket with 29.3 seconds left gave the sixth-seeded Tigers (19-11) a 65-63 lead, but Johnson hit the first of two foul shots with 13.2 seconds remaining to cut the margin to one.
He missed the second free throw, but third-seeded Oklahoma (24-6) got the ball back when Missouri's Kareem Rush and T.J. Soyoye collided going for the rebound and the ball went out of bounds.
The miscue spoiled an outstanding shooting night by Rush, who hit five three-pointers and led the Tigers with 31 points in just his third game back from surgery on the thumb of his shooting hand.
Johnson who finished with 20 points then scored on a driving layup with 3.2 seconds left to give Oklahoma a 66-65 lead, and Missouri threw the ball away at the other end of the court.
Aaron McGhee hit one more free throw for the Sooners with 2.9 seconds to go and then stole the inbounds pass after a Missouri timeout.
No. 20 Texas 55, Oklahoma State 54
Kansas City, Mo. Oklahoma State started slowly in the second half and was knocked out of the Big 12 tournament.
Chris Owens scored 12 points, and Brandon Mouton made the defensive play of the game as Texas slipped past the Cowboys.
The Longhorns (24-7) won their seventh game in a row.
Texas had its lead cut to one when Oklahoma State's Maurice Baker hit his fourth three-pointer with 44 seconds to go. After Brian Boddicker missed from the baseline for Texas, Victor Williams grabbed the rebound and passed to Baker.
But as Baker who scored 20 points drove in for the potential go-ahead bucket, Mouton tied up the Cowboys' All-Big 12 guard and the Longhorns got the ball on the alternate possession.