LAWRENCE — Saturday was supposed to be a day of celebration for Kansas basketball, commemorating the program’s 120 years with reunions and acknowledgements.

It instead became a day to forget for the Jayhawks — though history would again be made.

No. 7-ranked KU suffered its third defeat at Allen Fieldhouse on the season, this time an 84-79 decision to 12-point underdog Oklahoma State. It marks the first time the Jayhawks have dropped a trio of true home contests in coach Bill Self’s 14-plus-year tenure — in fact, no single KU team since 1998-99 had suffered three defeats at “The Phog.”

“Hopefully the guys that came back, it won’t take away from them enjoying their teammates and stuff,” Self said. “But obviously it takes away from the day, not playing better.”

Self told his team following a Jan. 2 home setback to Texas Tech that it wouldn’t be the last time the group left Allen Fieldhouse upset, and those words proved prophetic Saturday on an afternoon where the Cowboys shot 51.6 percent from the field, made 12 3-pointers and held a 26-7 advantage in second-chance points.

“There were just better than us today right from the jump — so much more athletic and quicker and more competitive,” Self said. “We got what we deserved.”

Kendall Smith (24 points) and Cameron McGriff (20 points) played unlikely heroes for OSU, which entered seventh in the Big 12. First-place KU, meanwhile, cut what was once an 18-point deficit to three, 82-79, with 14.2 seconds to play, but Smith made a pair of free throws to ice the outcome.

“I mean, to think that we had a chance to be in that game if we scored is pretty amazing to me,” Self said, “because I think we got whipped in pretty much every facet.”

Two missed front-ends of one-and-ones from the stripe in the final minute gave the Jayhawks (18-5, 7-3 Big 12) an opening to get even closer, but down five with 23 seconds left, Svi Mykhailiuk committed a costly turnover trying to find Marcus Garrett in the paint.

It was KU’s 11th and final turnover, but OSU (14-9, 4-6) scored 20 points off those giveaways.

“It’s a bad play,” Self said of Mykhailiuk’s turnover. “He’s just trying too hard. Was (Garrett) open for a second? Yeah, but the pass had no chance to get through.”

Udoka Azubuike (20 points, 8-for-11 shooting) paced the KU offense but brought in only five rebounds as the Jayhawks were beaten on the boards, 41-28. OSU secured 16 offensive rebounds and capitalized to the tune of a 26-7 advantage in second-chance points, with 13 of those offensive rebounds and 22 of the second-chance points coming in a first half which saw the Cowboys enter the break with a 13-point advantage.

Self said the Jayhawks’ two best rebounders, Azubuike and Lagerald Vick, were the team’s worst against the Cowboys.

“That’s the least competitive (rebounding) I’ve ever seen,” Self said. “They had a couple rebounds we walked away from (and) gave them uncontested baskets. That’s our Achilles’ heel all year long, and it was today.”

The outcome was first-year OSU coach Mike Boynton’s first career road victory and matched the number of wins legendary Cowboy coach Eddie Sutton earned in 13 total tries here.

“I don’t know if I want to be trying to say I’m anything better than him at all. I’ve got a long way to go,” Boynton said. “I think I’m at 14 (career victories); he was at 800-something. So he’s won at a lot more places than I have, that’s for sure.”

The Cowboys, who entered ninth in the Big 12 in 3-point accuracy (33.1 percent), made 44.4 percent of their 27 attempts against the Jayhawks. KU, meanwhile, made only 8 of 22 attempts from beyond the arc. Mykhailiuk (17 points) and Devonte’ Graham (17 points) made 3s with 1:09 and 42 seconds remaining, respectively, to help KU claw back, but Smith’s free-throw makes pushed the lead to five with 10 seconds left, too steep a deficit to overcome.

“It’s very frustrating, ’cause you’re supposed to win the home games and it’s supposed to be really tough on the road,” Graham said. “We’ve kind of got it flip-flopped this year. We’re way better on the road than we have been playing at home. We’ve just got to find a way to come out and crush teams like how they came out and put their foot on our throat today.”

The defeat dropped the Jayhawks into a tie in the Big 12 loss column with Texas Tech and Oklahoma, who both played later Saturday. KU is seeking its national record-breaking 14th consecutive regular-season conference championship.

“We had a one-game lead in the league, which that’s obviously gone, but it’s not even a one-game lead,” Self said. “Hey, you could lose four games in a row in this league or you could win four in a row. It’s been proven by other teams. The league is so good, and if you don’t bring it at all and the other team plays well, you’re going to get beat, and certainly that’s been the case with us.”