Kansas State had Oklahoma on the ropes, but in the end it was the Wildcats who hung themselves.
Oklahoma shut K-State out for 3 minutes, 45 seconds, while scoring the game's last 12 points Saturday afternoon to erase a seven-point deficit and claim a 66-61 victory over the Wildcats at the Lloyd Noble Center in Norman, Okla.
Three of the Wildcats' six second-half turnovers came in the final 2 minutes, 12 seconds, and they missed their last five shots from the field.
"Too many turnovers," K-State coach Bruce Weber said. "Down the stretch we had empty possessions and (Oklahoma's Kristian) Doolittle outhustled us on two or three rebounds down the stretch.
"A tough loss. We led most of the game (and) our guys did a lot of good things. We played a lot of young guys, but we didn't find a way to win."
The Wildcats, who fell to 7-6 overall and 0-1 in the Big 12, led 61-54 when DaJuan Gordon knocked down a 3-pointer at the 3:45 mark. But De'Vion Harmon drove from the right wing for a layup with 3:24 to go that started the Sooners (10-3, 1-0) on the decisive run.
Austin Reaves gave OU its first lead of the half and only the second of the game, 63-61, on a 3-pointer with 1:39 to go. Reaves, a junior transfer from Wichita State, scored 18 of his team-high 21 points in the second half.
K-State still had a chance, trailing by four, when Xavier Sneed's 3-point shot went in the basket and rolled out with 23 seconds left. The Wildcats kept possession, but immediately turned the ball over.
"He got a great look on the corner play that we drew up," Weber said. "They go zone (late), credit to Lon (Kruger, OU coach). They played zone one time maybe all year."
After going 7 for 16 from 3-point range in the first half, the Wildcats were just 5 of 21 after intermission.
K-State led most of the game, taking a 33-30 advantage to halftime and starting the second period with an 11-3 spurt to go up 44-33 on Montavious Murphy's free throw with 14:25 left. Cartier Diarra and Sneed each hit 3-pointers during the run.
Sneed, who led all scorers with 22 points, also had a four-point play and another 3-pointer at the 10:59 mark to stop a mini-run by OU and stretch the lead back to 51-41.
But that's when Reaves got going, hitting two free throws for the first of seven straight points. He also knocked down a 3-pointer with 5:06 left that got the Sooners within a point at 55-54, only to see K-State answer with six straight, capped by Gordon's three.
For Oklahoma, Reaves was joined in double figures by Kristian Doolittle with 19 points and 12 rebounds, while Brady Manek had nine points and nine boards.
Sneed guarded Reaves successfully for much of the game, but was saddled with four fouls down the stretch, forcing Weber to look elsewhere.
"I thought we had Reaves pretty under control," Weber said. "(But) obviously not the last five, six minutes where he got cooking and made the plays that gave them a chance."
It was a familiar scenario for K-State, which has failed to finish in close games down the stretch for much of the season.
"We've been in a position in all our losses this year, either up or down by five, two or three, with three or four minutes to go," Sneed said. "We've been working on situations in practice. We've just got to execute in the game."
Diarra added 10 points, 7 assists and 6 rebounds for K-State. Antonio Gordon led the Wildcats with eight rebounds.
K-State shot just 29.4% in the second half, 34.9% for the game. Oklahoma shot 37.3% and made just 5 of 23 3-point attempts, but outscored the Wildcats from the free-throw line, 23-5, and also had a 42-37 rebounding advantage.
The Wildcats play their conference home opener at 8 p.m. Tuesday night against TCU at Bramlage Coliseum.