Naadir Tharpe scored 21 points for Kansas, and Frank Mason stripped Oklahoma State's Le'Bryan Nash as the final buzzer sounded to preserve the 15th-ranked Jayhawks' 80-78 victory over the ninth-ranked Cowboys on Saturday.
Joel Embiid added 13 points, 11 rebounds and eight blocks for the Jayhawks (13-4, 4-0 Big 12), who blew most of a 47-30 halftime lead before holding on at the finish.
Phil Forte hit seven 3-pointers and had 21 points for Oklahoma State (15-3, 3-2). Marcus Smart added 16 points, but he was just 3 of 14 from the field and 0 for 6 from behind the 3-point arc.
Still, Smart nearly gave the Cowboys a chance. His layup with 24 seconds remaining got them within 79-75, and after Mason missed a free throw, Forte hit a 3-pointer to make it a one-point game with 5.7 seconds remaining.
Mason was fouled and made the first of two free throws, and the Cowboys raced up court with the rebound on the miss. Nash tried to get off a shot from just beyond the arc as time expired, but Mason was there to pop the ball loose and preserve the victory.
Markel Brown finished with 15 points for Oklahoma State while Kamari Murphy had 12 and Nash finished with 10.
The testy game included six flagrant or technical fouls.
The animosity between the teams really started to simmer last season, when the Cowboys came into Allen Fieldhouse and ended the Jayhawks' 33-game home win streak. Smart celebrated by doing a backflip, a stunt captured on film that Kansas coach Bill Self showed his team this week
It reached a rolling boil shortly before the season, when Smart declared that Kansas' Andrew Wiggins had yet to warrant the considerable hype that the star freshman had been receiving.
Naturally, most figured that Smart and Wiggins would be the leading characters when their teams met. Instead, two uber-talented players expected to be chosen early in June's NBA draft were relegated to supporting roles as their teammates stepped into the spotlight.
Kansas delivered the game's first big blow midway through the first half, ripping off a 13-0 run fueled by Tariq Black's monstrous dunk. By the time Brown's turnover led to a run-out basket by Black and a 29-15 lead with just under 8 minutes left in the half, a sellout crowd that included Green Bay Packers quarterback Aaron Rodgers was roaring its approval.
In fact, the noise was so deafening that Brown didn't hear Oklahoma State coach Travis Ford call a timeout. He instead raced up court and found himself in the midst of the Kansas huddle, and wound up triggering a benches-clearing fracas that the officials had to separate.
Brown and the Jayhawks' Jamari Traylor were each hit with technical fouls.
Things didn't cool off, either. Later in the half, Smart was hammered by Wayne Selden on his way to the rim. Selden was promptly shoved by the Cowboys' Stevie Clark, drawing another technical.
Kansas led 47-30 at halftime.
The Cowboys tried to mount a comeback on the second half. Forte got hot from behind the arc, and Brown hit four 3-pointers in the span of a few minutes, the last of them closing Oklahoma State within 59-56 with 11:02 remaining.
Kansas stoically answered the challenge.
Mason's 3-pointer triggered seven straight points by the Jayhawks, and when Smart finally hit his first field goal with 5:53 left in the game, Embiid answered with a thunderous jam off an alley-oop pass that left the entire goal setup trembling.
As the Jayhawks slowly rebuilt their lead, Oklahoma State began to lose its poise. Brown was whistled for a foul on Embiid, and voiced his frustration within earshot of official John Higgins, earning his second technical of the game. It also resulted in him fouling out.
The Cowboys got within 77-73 on a basket by Smart with 1:29 left, but Tharpe answered again with a 3-pointer from the top of the key. The Jayhawks then held on in the closing seconds to put some distance on Oklahoma State in the Big 12 race.