LAWRENCE, Kan. (AP) -- Markel Brown scored 28 points, Marcus Smart added 25 and Oklahoma State held on to upset No. 2 Kansas 85-80 on Saturday, ending the Jayhawks' nation-leading 18-game winning streak.
Smart had a pair of key put-backs in the closing minutes, helping the Cowboys (15-5, 5-3 Big 12) go on a 13-2 run that turned a 66-62 deficit into a 73-68 lead with just over a minute left.
The Jayhawks (19-2, 7-1) managed to play savvy defense and take advantage of a couple missed free throws, trimming the Cowboys' lead to 81-80 on a layup by Elijah Johnson with 18.8 seconds left.
But unflappable freshman Phil Forte, an 89-percent foul shooter, made both of his tries with 7.9 seconds to go, and Johnson turned the ball over before Kansas could try a tying 3-pointer.
Forte even converted the turnover into a buzzer-beating layup, punctuating the Cowboys' first road win over a top-5 team since beating then-No. 2 Kansas 52-50 in overtime on Jan. 2, 1958.
Forte finished with 11 points for the Cowboys, all of them coming in the second half.
Ben McLemore had 23 points to lead the Jayhawks, who also had their 33-game home winning streak come to an end in their first home loss to Oklahoma State since Feb. 8, 1989.
Kevin Young added 12 points and Jeff Withey had 11 for the Jayhawks.
Johnson's turnover in the closing seconds was the 16th of the game for Kansas, which had to rally from a 14-point first-half hole in part because of the turnovers.
Oklahoma State tried to bury the Jayhawks in the first 10 minutes of the game.
The Jayhawks led 9-7 when Smart was fouled shooting a 3-pointer. He made all three free throws to jumpstart a 19-3 run that covered the next 5 minutes. Brown scored 11 during the spurt, including a pair of 3-pointers that left Jayhawks coach Bill Self screaming on the sideline.
By the time Brown was fouled by Johnson and converted the three-point play with 10:58 left in the half, Oklahoma State had a 26-12 lead - the largest on Kansas all season.
Before that, the Jayhawks' biggest deficit was 12 against Chattanooga on Nov. 15.
Kansas went seven straight possessions without a basket, turning it over four times, before McLemore ended the drought with a field goal that started an 11-3 surge of its own.
Young had six points during the stretch. It ended when he forced Brown into a turnover under the Oklahoma State basket, ran the length of the court and elevated as high as he possibly could to snare a pass from Naadir Tharpe and lay in the basket with 6:30 left in the half.
Oklahoma State quickly called time out and, on cue, Brown delivered another 3-pointer.
The Cowboys' junior guard finished the half with 22 points, just two off his season high. He was 7 of 10 from the field, 5 of 7 from the arc and even had a couple assists.
Brown hit another 3 out of halftime, but that's when McLemore started to take over.
The Jayhawks' freshman scored off a missed basket, finished a pair of alley-oop feeds from Johnson near the rim, and hit his own 3 with 15:14 left to give Kansas a 46-45 lead. McLemore added a driving layup during the run, and another lay-in with 13:23 remaining finished off a 16-4 momentum swing.
Smart and Brown refused to let the Cowboys wilt, though.
Smart scored back-to-back baskets, and after missing his first eight field-goal attempts, Forte finally got on the board. Brown then hit his seventh 3 from the wing that pulled Oklahoma State within 59-58 with just over 8 minutes left in the game.
Forte added his first 3 moments later, and Michael Cobbins followed up a miss by Forte with a massive dunk that allowed the Cowboys to regain a 67-66 lead with 3:45 remaining.
Le'Bryan Nash's shot clock-beating jumper with 2:40 to go gave Oklahoma State a 69-68 lead, and despite some tense moments down the stretch, the Cowboys never trailed again.