PROVO — By halftime of No. 19 BYU’s regular-season finale Saturday night against Houston, the host Cougars had been eliminated as contenders for the Big 12 championship thanks to Iowa State’s 29-21 victory over Kansas State.

BYU’s defense did not receive the memo.

Jake Retzlaff threw for 167 yards and ran for 57 yards and two touchdowns, and BYU’s defense forced four turnovers and seven tackles for a loss to complete a two-game series with a 30-18 victory over Houston before an announced crowd of 59,213 fans. Slips to be scored at LaVell Edwards Stadium.

LJ Martin ran for 87 yards on 22 carries for BYU (10-2, 7-2 Big 12), which has totaled double-digit wins in three of the last five years. Chase Roberts caught three passes for 76 yards to lead BYU in rushing on a night the redshirt junior celebrated as his senior night.

Houston sophomore Zeon Chriss threw for 156 yards with one interception and ran for two touchdowns.

But BYU’s defense, led by 13 tackles from Tanner Wall and nine tackles, 2.5 tackles for loss and an interception from Tyler Batty, held the Cougars to 250 yards of offense, including 94 on the ground.

Houston (4-8, 3-6 Big 12) struck first after both Cougars groups traded first turnovers, and Zeon Chriss led a 10-play, 80-yard drive that ended with a 3-yard quarterback keeper ended, which went up 7-0.

However, the lead only lasted seven seconds when the visitors attempted an onside kick and Talan Alfrey picked up the change and returned it 58 yards for a touchdown.

It was BYU’s third kick return touchdown of the year, matching Paul Allen’s three kick return touchdowns in 1961.

But the hosts weren’t done with defense and special teams.

Jack Kelly and Batty each had an interception, bringing BYU’s total to 20 on the year, tied for the most in the country, and Isaiah Glasker had a sack among the hosts’ seven tackles for a loss.

Retzlaff completed 6 of 12 passes for 110 yards, including a 52-yarder to Chase Roberts in the final two minutes of the first half to set up his own 13-yard TD rush that gave BYU a 21-10 halftime lead .

It could have been more.

BYU outscored the Cougars 90 to 32 yards in the third quarter. But Retzlaff fumbled a high snap just four yards from goal, and Parker Kingston parried a punt at midfield as the only score of the period came on Will Ferrin’s 22-yard field goal.

Houston got within eight on Chriss’ second touchdown run – and scored a 2-point conversion – with 8:34 left to play.

But BYU’s defense saved the game again as Kelly recorded his fifth sack of the season and Blake Mangelson recovered a fumble to set up Retzlaff’s second rushing score with 2:52 left.

This story will be updated.