Marquis Gilstrap scored eight of his 17 points in double overtime and Iowa State held off Houston 82-75 on Sunday afternoon for its fourth straight win.
Lucca Staiger had 18 points and Craig Brackins added 16 points and 11 rebounds for the Cyclones (10-3), who outscored the Cougars 13-6 in the second overtime period to pick up their fourth straight win.
Houston's Maurice McNeil hit a putback with 1.7 seconds left to force overtime, and Iowa State's Diante Garrett hit a layup to force another OT.
Gilstrap then put the Cyclones on his shoulders, hitting three quick buckets to put Iowa State ahead 78-71 with 1:44 left.
Aubrey Coleman, the nation's leading scorer entering Sunday, had 28 points and nine rebounds for Houston (7-6), which lost its third straight.
After 45 minutes of back-and-forth basketball, the second overtime was all Iowa State.
Gilstrap opened the frame with a jumper. Staiger then buried a 3-pointer to make it 74-69, and Gilstrap followed with two tough layups through traffic to give the Cyclones a 78-71 lead with 1:44 left.
Gilstrap put an exclamation point on a wild win with a layup with 18 seconds left, flexing his biceps to the crowd after being fouled.
The Cyclones hadn't played in 11 days - and it looked like it until the final five minutes.
Coleman followed a layup with a jumper at the top of the key to put Houston ahead 68-65 with 1:37 left in the first overtime. Brackins hit two free throws to pull Iowa State within one, but Houston's Zamal Nixon forced a jump ball after he missed a jumper.
The Cougars held the possession arrow, and Adam Brown hit one of two free throws.
That's when Garrett saved the Cyclones' necks, driving through the lane for a layup with 9.1 seconds left to send the game into double overtime.
Nixon missed a free throw with 12 seconds left in regulation and the Cougars down two. But Coleman grabbed the loose ball, and after he missed a jumper, McNeil's putback sent the game into overtime.
Iowa State took its first lead of the second half, 57-56, with 4:21 left as Garrett hit a tough layup in traffic. The Cougars scored their first points in over five minutes to jump back ahead 58-57 with 2:12 left, but Brackins then went to the line with a chance to tie it with 38 seconds left in regulation.
Brackins' second try hit the back of the rim and the Cougars got the ball back, but Staiger grabbed an errant Coleman pass and alertly hit Garrett in stride to make it 61-59.
Houston maintained a slim lead early in the second half until Staiger buried 3 straight 3s, all from different parts of the floor, to tie the game at 48 with 12:54 left. Kelvin Lewis put the Cougars back on top 56-53 with a 3 with 7:20 left.
This was yet another brutal loss for the Cougars, who lost to Louisiana Tech at home, 99-94, and on New Year's Day to host Texas-San Antonio, 83-82, when Nixon missed a layup at the buzzer.
Coleman bounced back from his worst game of the year, though. After scoring just 10 points on 2-of-12 shooting in the loss at UTSA, he shot 13-of-28 from the field and added three steals.
