Keenum completed 30 of 45 passes for 318 yards, a modest day for the nation's leader in total offense and pass efficiency. He set the completions mark on his seventh throw, breaking the previous mark (1,403) set by Texas Tech's Graham Harrell (2005-08).
The Cougars' sixth-year quarterback also joined Hawaii's Tim Chang as the only quarterbacks to reach 4,000 yards passing in three seasons, and he tied Chang's FBS record for career 300-yard passing games (36). Chang set his records in 2000-04, when he played for current SMU coach June Jones.
Houston (11-0, 7-0 Conference USA) relied more on its unheralded defense than its top-ranked offense to beat the Mustangs (6-5, 4-3) for the ninth time in 10 meetings.
SMU mustered only 263 yards and didn't score until J.J. McDermott threw a short touchdown pass to Darius Johnson with 8:33 left in the game. The Mustangs had 93 yards and six first downs in the first half and trailed 13-0.
Houston had scored at least 56 points in its past five games, but met more resistance than it has in more than a month on its opening series.
The Mustangs pressured Keenum with blitzes and sacked him once. The Cougars settled for Matt Hogan's 28-yard field goal to finish their most time-consuming scoring drive of the season -- 17 plays in 5 minutes, 58 seconds.
Keenum became the FBS leader in completions on Houston's next series, with a 22-yard pass to running back Bryce Beall. Earlier this season, Keenum eclipsed Chang's FBS career records for total offense and passing yards and Harrell's record for touchdown throws.
Hogan kicked another field goal, while SMU struggled even more to move the ball against Houston's defense.
J.R. Richardson returned the ensuing kickoff to midfield, and Matt Stone picked up a first down on a fake punt. Houston outside linebacker Sammy Brown, the nation's leader in tackles for loss, then sacked McDermott and Mike Loftus missed a 35-yard field-goal attempt. Loftus replaced regular kicker Chase Hoover, who sat out with an illness.
Keenum took a hard shot on a 5-yard run to the Mustangs' 36 late in the half, and Michael Hayes weaved through the SMU defense for the game's first touchdown with 46 seconds left before the break.
McDermott finally got the Mustangs moving early in the third quarter, and found Cole Beasley down the sideline for a 27-yard gain to the Houston 4. But on third down, linebacker Phillip Steward intercepted a McDermott pass in the end zone.
Hayes took a screen pass 60 yards to the SMU 2, and Hogan kicked another field goal for a 16-0 lead. McDermott then fumbled on a scramble near midfield, safety Kent Brooks recovered.
On fourth-and-1 from the SMU 12, Keenum faked a handoff to Hayes, and threw a short pass to Justin Johnson, who sprinted to the end zone with 30 seconds left in the third quarter.
Keenum went over 300 yards passing in the fourth, just before running 16 yards for a touchdown with 6:17 remaining. Backup quarterback Cotton Turner threw a 43-yard touchdown pass to Gino Collins five minutes later to put Houston over 35 points for the 11th straight game.
Hogan is 78-for-78 on extra-point kicks this season, an FBS record.
The Mustangs played without Conference USA leading rusher Zach Line, who underwent season-ending toe surgery on Thursday. Line, a junior, had reached 100 yards in eight of 10 starts this season.
The announced attendance was 32,207, a Robertson Stadium record.
(Copyright ©2011 by The Associated Press. All Rights Reserved.)
The University of Houston was in the national spotlight Saturday as the host of ESPN's College GameDay crew.
ESPN's College GameDay was broadcast from the southeast Houston campus Friday afternoon and again Saturday.
"[There is] a lot of excitement among our students a lot of excitement about our undefeated football team," said David Reiter with the University of Houston.
ESPN set up on Cullen Circle. Fans began entering at 4am Saturday and the circle was packed by the time the broadcast began at 8am.
This was College GameDay's first broadcast from the University of Houston campus, and the show's first visit to Houston since 2005.
Fans were excited the university is getting this kind of national exposure.
UH is now one of only two unbeaten teams in the country -- with LSU -- after Oklahoma State was blindsided by the underdog Iowa State on Friday night.
If the Coogs can win their remaining regular season games and the Conference USA championship game, a BCS Bowl invite could be in their future.
Cougars quarterback Case Keenum is also a Heisman candidate.
(Copyright ©2011 KTRK-TV/DT. All Rights Reserved.)