For Tulane, the misery commenced shortly thereafter.
Case Keenum threw for 334 yards and two scores, and Houston exploded for 37 second-half points in a 44-16 victory over the Green Wave on Saturday.
"It just didn't look like to me we were having any fun" in the first half, Sumlin said. "It looked like we were out here, not going through the motions, but just pressing. We had some things that were a little bit off early in the first half and guys were beating themselves up at halftime. We'd only given up two field goals, so there wasn't any reason to panic. They needed to just play." v Bryce Beall and Justin Johnson each ran for two touchdowns for Houston (5-1, 1-1 Conference USA), which pulled away convincingly after leading only 9-6 at the half.
Keenum wound up with his lowest passing total of the season, but still surpassed 300 yards for the 19th time in his career and the sixth straight game this season. His scoring passes went for 6 yards James Cleveland and for 7 yards to L.J. Castile.
"Tulane came in and had a really good game-plan. They did a good job of keeping us on our heels in the first half," Keenum said. "We just had to let loose and play. We were all kind of uptight and we just needed to go out there and have fun and play football because it's a fun game to play."
It certainly was in the end for Houston.
Tulane (2-4, 0-3), however, has now lost 37 straight to ranked teams since 1982.
Green Wave starting quarterback Joe Kemp had another inconsistent outing, going 10 of 15 for 124 yards, an interception and drive-stalling sack. For a second straight game, he was replaced in the second half by redshirt freshman Ryan Griffin, who produced Tulane's only touchdown on a 3-yard pass to Antoine Duplessis in the back of the end zone early in the fourth quarter.
Houston was in command by then, though, and responded with another touchdown of its own on Johnson's 6-yard run to make it 37-13.
"It was like a 12-round fight. They eventually wore us down and knocked us out," Tulane coach Bob Toledo said. "You're talking about one of the best offensive teams in the country, the best quarterback in the country. They score a lot of points -- and they did."
Tulane's Andre Anderson ran for 108 yards on 18 carries. Griffin finished 12 of 18 for 126 yards.
Cougars receiver Chaz Rodriguez had six catches for 84 yards, including a 34-yarder that was Houston's longest gain from scrimmage.
Houston entered the game averaging 569.2 yards and 40.2 points per game, but Tulane's defense, rated first against the pass in Conference USA coming in, slowed the Cougars early.
Clock-eating drives powered by Anderson's hard running led to Ross Thevenot's field goals of 43 and 35 yards, the second putting Tulane ahead 6-3 with 11:03 left in the first half.
Houston got going after that, responding with a 12-play, 66-yard touchdown drive capped by Beall's 1-yard scoring run. The series demonstrated how quickly the Cougars can move the ball with their no-huddle attack. They consumed just 2:38 on the drive. Ben Bell's point-after try missed, keeping Houston's lead at 9-6.
Houston again drove deep into Tulane territory a few minutes before halftime, but Bell hooked a short field goal try wide left.
The Cougars went up 15-6 on the opening drive of the second half, needing only 1:58 to cover 60 yards in eight plays. The drive ended with Johnson's 3-yard run for his first career touchdown.
Houston struck again after Jeremy Smith blocked Thevenot's punt deep in Green Wave territory. Two plays later, Keenum rolled right and found Cleveland in the back of the end zone to make it 22-6.
"I was proud of them. When you're on the road, we talk about creating your own energy," Sumlin said. "You couldn't have a better series of events than that to start the second half."