Baylor (15-2, 3-2 Big 12) had won a national-best 21 games in a row dating back to last season 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 while traveling more than 3,200 miles.
After trailing by as many as 17 points in the second half, the Bears were within 55-54 with 1:21 left when LJ Cryer made two free throws to cap a 14-2 run. They didn't score again.
"They're not very happy,'' Bears senior Matthew Mayer said when asked the mood of the coaches.
"We dug ourselves in a big hole. ... If the hole wasn't that big, then we would have been able to win the game,'' said Cryer, who had 18 points and didn't sense any hangover from the loss to Tech. "I felt like that had nothing to do with this loss.''
Cowboys guard Bryce Thompson scored the game's final six points and finished with 18. He made two free throws with 26 seconds left before 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 and made two more free throws before a game-capping breakaway dunk after Baylor missed its last shot.
The Cowboys (9-7, 2-3 Big 12) began their week with a 10-point loss at West Virginia on Tuesday, then two nights later lost 78-57 at Texas Tech, after the Red Raiders had just beaten Baylor at the Ferrell Center.
"It's been one heck of a week in terms of what we've had to face competition-wise and travel-wise,'' Oklahoma State coach Mike Boynton said. "But for those guys to show the resilience, and the determination and courage to come out and play with the amount of energy that was required ... If we play with any little less energy, we lose the game.''
The only time Oklahoma State trailed was after Kendall Brown's basket that made it 4-3 only 2:30 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 clock expired, but there was no whistle when Rondel Walker stole the ball and passed to Keylan Boone for a breakaway layup.
"Credit Oklahoma State. Again, shows how good our league is,'' Baylor coach Scott Drew said.
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.
Mayer had a 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.
The Associated Press and ESPN Stats & Information contributed to this story.