Clayton Tune's two-point conversion was successful thanks to an 8-yard run in the third overtime as visiting No. 24 Houston outlasted Texas-San Antonio 37-35 on Saturday afternoon in a wild season-opening game for both teams in San Antonio.

Both teams were forced to settle for field goals in the first overtime, with Houston's Bubba Baxa hitting from 35 yards and the Roadrunners' Jared Sackett answering with a 39-yarder.

The Cougars then scored on a 1-yard run by quarterback Tune and a pass to Nathan Dell on the mandatory two-point conversion. UTSA countered with 13-yard TD pass from Frank Harris to De'Corian Clark, and Harris rushed for the two-point conversion on its possession in the second OT.

Tune then scored the game-winner from added distance because of a false start, after which Harris' pass was incomplete on the Roadrunners' attempt in the third overtime.

Tune finished with three passing touchdowns and one score on the ground for Houston while amassing 257 total yards (206 passing, 51 rushing).

Harris passed for 337 yards and three touchdowns and ran for a game-high 63 yards for UTSA.

The Cougars struck first when Tune and Dell hooked up for an 11-yard TD pass on the third snap of the second quarter.

UTSA answered on its ensuing possession, with Harris hitting Joshua Cephus on a 51-yard touchdown. Harris then scrambled for a 38-yard score to give UTSA its first lead at the 6:30 mark of the second quarter.

Harris then found Clark for a 15-yard touchdown with 4:12 to play in the third quarter to produce a 21-7 lead for the Roadrunners.

Houston responded with a nine-play, 75-yard march that culminated with the second TD pass from Tune to Dell, this one covering 10 yards and bringing the Cougars back to within seven points after Baxa's extra point.

Houston took advantage of an interception and return of 32 yards by Nelson Ceaser when Tune passed 20 yards to Joseph Manjack IV on the following snap for the game-tying touchdown with 12:19 to play in regulation.

The Cougars took the lead on Baxa's 35-yard field goal with 23 seconds remaining after an 18-play drive. But UTSA, with no timeouts, moved into field goal range with two completions to set the table for Sackett's 37-yard field goal on the final snap of regulation.

--Field Level Media