The Bears are certain to lose their spot at the top of the AP Top 25 when the new poll comes out Monday.
After trailing by as many as 17 points in the second half, Baylor was within 55-54 when LJ Cryer made two free throws to cap a 14-2 run.
Thompson made two free throws with 26 seconds left, then Bears guard Adam Flagler had turnovers on consecutive possessions — losing the ball out of bounds on a drive to the basket, then a bad pass. Thompson was fouled making the steal, then hit two more free throws before a game-capping breakaway dunk after Baylor missed its last shot.
Cryer had 18 points for Baylor (15-2, 3-2 Big 12), which had won a national-best 21 games in a row before its loss Tuesday night at home to Texas Tech. The reigning national and Big 12 champions led for only 16 seconds Saturday against an Oklahoma State team playing its third Big 12 road game in five days.
The only time the Cowboys (9-7, 2-3) trailed was after Kendall Brown’s basket that made it 4-3 only 2 1/2 minutes into the game. The Bears then missed 10 shots in a row over a span of more than six minutes before Cryer’s 3-pointer from the top of the key.
Oklahoma State followed that with another 12-2 run and had their biggest lead at 29-11 when Isaac Likekele made a short floater off the glass. There was one possession in that stretch when Baylor didn’t even get a shot off before the 30-second shot clock expired, but there was no whistle when Rondel Walker stole the ball and passed to Keylan Boone for a breakway layup.
Oklahoma State was coming off a 78-57 loss on Thursday night at Texas Tech, a makeup of a Jan. 1 game postponed because of COVID-19 issues in the Cowboys program.
Baylor hadn’t had consecutive losses since the last three regular-season games of the 2018-19 season and its Big 12 tournament opener. The Bears also hadn’t lost back-to-back games at home since the end of the 2015-16 season.
Matthew Mayer had season-high 16 points for the Bears, who shot a season-low 31% (18 of 58). Their 22 points before halftime were their fewest in a half this season, and the 57 points overall were also a season low.
Oklahoma State: The Cowboys beat a No. 1 team on the road for the first time in school history. … Thompson was the only player scoring in double figures for the Cowboys, but all nine players who got into the game had at least nine points, and eight of them had multiple rebounds.
Baylor: Already short-handed with forward Jeremy Sochan sitting for the second game in a row after turning his left ankle last weekend, the Bears also were without leading scorer James Akinjo for the final 9:49. Akinjo came down hard on his rear end against Texas Tech, and is still sore from that. He did play 23 minutes, making only 1 of his 8 shots.
After five consecutive weeks at No. 1, the last three unanimously, Baylor should still extend a school record with their 40th consecutive poll in the Top 10 when the new poll comes out Monday.
Oklahoma State: Hosts TCU on Wednesday.
Baylor: At West Virginia on Tuesday.