A 52.5 percent shooter from the free-throw line, Thornton hit 9 of 9 at the charity stripe while also drilling 4 of 5 3-point attempts in the upset. Jimario Rivers added 21 points and nine rebounds for Memphis, which has won three consecutive games since adopting a zone defense.

The Cougars (21-6, 11-4 American Athletic Conference) had their five-game winning streak snapped and fell off the pace in the league. Houston had been tied with Wichita State a game behind first-place Cincinnati.

Rob Gray led the Cougars with 30 points while Corey Davis Jr. and Armoni Brooks scored 15 apiece.

Thornton was at the heart of the surge that produced a lead for Memphis (17-11, 8-7).

With Houston leading 58-51, Thornton stroked a pair of 3-pointers to key the resurgence. His two free throws at the 10:52 mark gave the Tigers the lead at 63-62 and ended a long crawl back from a 13-point hole, a stretch that included Memphis repeatedly cutting the margin to three only to fall back into a greater deficit.

When Thornton absorbed a foul while shooting a 3-point attempt with 7:11 left, he converted all three shots from the line to lift the Tigers to a 74-68 lead. One possession later, Memphis led by eight.

The Cougars seized the lead in the first half on the strength of their defense, holding Memphis without a field goal for more than five minutes while fashioning an 18-2 run. Houston buried four 3-pointers during that surge with Gray producing 10 points.

Jeremiah Martin pulled the Tigers back into contention with a step-back jumper, a second-chance basket and a 3-pointer that cut the deficit to 27-24 before departing with an injury. With Martin sidelined, the Cougars reclaimed control, and when Brooks sank consecutive treys, Houston secured its largest lead of the half at 43-30 with just over a minute left.

Memphis mustered one final push, closing the half with a 7-0 run to cut the deficit to six at the break despite allowing Houston to amass 20 bench points while shooting 58.1 percent overall.

Martin, the leading scorer in the league, did not return. He was diagnosed with a foot injury.

For the game, Memphis outshot Houston 54.2 percent to 45.2 percent.

--Field Level Media