WACO, Texas (Ticker) -- Kansas was unable to overcome the worst first half in the Roy Williams era.
Wendell Greenleaf had a key 3-pointer and big assist down the stretch as Baylor improved its NCAA Tournament hopes with an 85-77 upset of the sixth-ranked Jayhawks, its first victory in seven tries against the Big 12 Conference power.
"This is terrific for our program because we have come a long way," Baylor coach Dave Bliss said.
Kansas, which trailed by 25 points at the break, fought within 69-64 on a follow by Nick Collison with 3:49 to play before Greenleaf gave the Bears some breathing room by draining a shot from beyond the arc on the left wing.
After Collison made the first of two free throws, Greenleaf's alley-oop pass to Terry Black, who had several thunderous dunks on the night, sent the fifth-largest crowd (9,523) in Ferrell Center history into a frenzy.
"I feel great right now," said Black, who scored 20 points. "It's not every day that you beat a great team like Kansas. My hat goes off to my teammates." Baylor sealed the victory by going 11-of-16 at the foul line in the final 2:36.
"Kansas took away our penetration game and we almost wilted down the stretch," Bliss said. "But we're grateful for the win." Kirk Hinrich scored 26 points for Kansas (19-4, 8-3 Big 12), which fell on Monday night for the third consecutive week.
Needing a big win in their search for the school's first NCAA Tournament bid since 1988, the Bears (16-6, 5-6), who snapped a 17-game losing streak against ranked opponents, scored the game's first 10 points and led 23-6 eight minutes into the contest.
The highlight of the opening half came with 3:44 to play when Black, a 6-5 senior, went high above the rim to throw down an alley-oop pass from DeMarcus Minor, giving the Bears a 40-18 lead.
"He has been known mostly for his dunks, but he's a great all-around player," Bliss said.
The Bears began the season 12-0 and joined Stanford, Boston College and Stanford as the last of the unbeatens before suffering their first loss of the campaign at Texas Tech on January 9.
That started a downward spiral for the Bears, who dropped five of their first seven Big 12 contests before righting themselves with recent victories over Texas Tech and Nebraska as they prepared for the season's biggest three-game stretch.
Baylor, with upcoming contests against 14th-ranked Oklahoma and Texas, came out on fire against the Jayhawks, who have dropped three of five games and must visit No. 9 Iowa State on Saturday.
Black's baseline jumper made it 10-0. Greenleaf scored the first seven points for Baylor in a 13-2 run shortly thereafter as the lead ballooned to 17. Black's acrobatic play put a punctuation mark on the first-half dominance.
Down 47-22 at the break, the Jayhawks faced their largest halftime deficit in 13 seasons under Williams.
The Bears picked up their first victory over a ranked team since a 97-95 double-overtime triumph against No. 25 Oklahoma State on January 17, 1998.
Greenleaf also scored 20 points and Minor added 15 with nine assists for Baylor, which shot 52 percent (28-of-54), going 7-of-17 from 3-point range, while holding Kansas to 43.5 percent (30-of-69).
Kansas held a 37-34 advantage on the boards behind Collison's nine rebounds but was 9-of-31 from 3-point range and was outscored at the foul line, 22-8.
Down 56-32 following a 3-pointer by Baylor's Logan Kosmalski, the Jayhawks put together a 23-6 run over a seven-minute span to get back into the contest.