Scuffling to find options on offense, Kansas State was in desperation mode as it tried to avoid a sixth consecutive loss.
Fresh off a three-game suspension, Marcus Foster provided just the boost the Wildcats needed.
Foster made a tiebreaking 3-pointer with 3.4 seconds left and scored 14 points to lead Kansas State past No.17 Oklahoma 59-56 on Saturday night.
"Since he's been in college he has always hit the big shots for us," teammate Nino Williams said. "We live and die on Marcus and he always takes the big shot. It's one he hits all the time."
It was the second time this season that Foster hit a late 3 to beat the Sooners (17-8, 8-5 Big 12). He also did it Jan. 10 in Norman, Oklahoma.
Buddy Hield had 14 points to pace Oklahoma but was held to his lowest point total since Jan. 5 against Baylor.
"They called me out to step up to the task and shut Buddy Hield down," Kansas State forward Wesley Iwundu said. "Coming into the game, that was my whole mindset, to focus on defense and make everything hard for them."
The Sooners matched their scoring low for the season set in a 69-56 loss to Wisconsin in the Bahamas.
"We defended, held them to 37 percent (shooting) and 56 points, with seven or eight points coming in the last stretch," Kansas State coach Bruce Weber said. "Those gave us a chance. To win a game and only shoot 26 percent and only have 13 field goals against a Top 25 team won't happen every day of the week."
Oklahoma coach Lon Kruger, a former Kansas State All-American, fell to 5-7 against his alma mater.
Kansas State (13-13, 6-7) established its late lead with only three field goals in the final 9 minutes. Free throw shooting was crucial as the Wildcats went 8 for 10 down the stretch and finished 28 of 36 for the game.
Following a dismal performance from the field in the first half, the Wildcats used a 13-2 run to push their lead to 42-37 with 12:02 left.
Kansas State's offense opened up when Oklahoma's top interior threat, Ryan Spangler, and reserve Khadeem Lattin left the game with four fouls each with more than 12 minutes remaining.
Spangler checked back in with 8:42 left and fouled out in less than 30 seconds. Thomas Gipson followed Spangler's exit with two free throws, equaling Kansas State's largest lead at 50-43.
"They were more aggressive than us at both ends of the floor," Sooners forward TaShawn Thomas said. "They were more aggressive and fought harder on each possession."
Foster made his return just before the first media timeout and immediately hit a 3.
But it wasn't all fun and games for the Wildcats. Oklahoma flexed its frontcourt muscles in the first half, scoring 14 points in the paint and grabbing eight offensive rebounds.
Kansas State shot just 23 percent from the field in the first half, but used the charity stripe (13 of 15) to close with a 28-27 deficit.
The Wildcats also held the Sooners to 1-of-11 shooting from 3-point range in the opening 20 minutes.
Kruger praised Weber for the way he's handled adversity this season.
"Every film looks the same in terms of great effort and intensity," Kruger said. "It is not easy to do when you have different things happening to your lineup, but Bruce has done a great job of dealing with that."
Spangler's early exit left the junior with his first single-digit scoring performance since Jan. 10 when he scored nine points against the Wildcats in Norman.
THAT WAS CLOSE
Kansas State avoided dropping two games under .500 for the first time since the end of the 2002-03 season when it finished 13-17.
Oklahoma: Kruger's team is holding opponents to 37.5 percent shooting this season. The last time the Sooners limited foes to less than 40 percent shooting in a full season was 1959-60.
Kansas State: The Wildcats' five-game losing streak was their longest since dropping six in a row in February 2005. The team was below .500 for the first time since Jan. 28, 2004.
Oklahoma hosts Texas on Tuesday.
Kansas State plays at TCU on Wednesday.
Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.