HONOLULU (AP) Backup quarterback Tyler Graunke replaced an injured Colt Brennan and provided Hawaii the spark it needed.
Graunke threw for three touchdowns in the third quarter and ran for another score as No. 16 Hawaii defeated Utah State 52-37 on Saturday night.
The victory gave the Warriors (6-0, 3-0 Western Athletic Conference) a school-record 10 straight conference wins and their best start since the 1981 team opened 7-0.
The Warriors, surprisingly, had a difficult time with the winless Aggies (0-6, 0-2), who extended their losing streak to 12 games.
Utah State, which hasn't won on the road since 2005 and dropped to 1-43 against ranked teams, were led by the play of Kevin Robinson.
Robinson returned a kickoff 100 yards for a touchdown and caught five passes for 96 yards, including a 77-yard TD catch that cut Hawaii's lead to 25.
Robinson's dazzling kickoff return gave the Aggies a 10-7 lead. The speedy Robinson caught the ball at the goal line and zigzagged his way until he found daylight near midfield. He ran untouched the rest of the way, bring to life the Aggies sideline while stunning the home crowd.
Utah State, which entered the game averaging just 15 points a game, kept Hawaii off balance with its mobile quarterback Leon Jackson III, who had 161 yards passing and 55 yards rushing.
The Aggies played confident and physical. They clearly were not intimidated by the Warriors.
Derrvin Speight's 9-yard TD run cut Hawaii's lead to 11 early in the third quarter, but that's as close as the Aggies would get as Graunke took over.
Peter Caldwell's 36-yard field goal early in the second quarter gave Utah State a 13-10 lead that it would hold for just 12 seconds. Malcolm Lane scored on an 87-yard kickoff return, giving Hawaii a 17-13 lead.
Brennan walked off the field on his own power after taking a hard hit with 52 seconds left in the first half with Hawaii leading 24-14. The Heisman Trophy hopeful completed a short pass when he was drilled by linebacker Paul Igboeli.
Recovering from a right ankle injury he suffered three weeks ago, Brennan laid on the field for a few minutes before slowly getting up and gingerly walking off the field.
He was replaced by Graunke who completed a 38-yard pass on his first pass to set up his 1-yard TD run that put Hawaii up 31-13. Graunke was initially ruled down with 5 seconds left in the half, but the call was overturned after a review.
Brennan, ranked second in the nation in passing, returned in the third quarter to a round of cheers and played one series before limping off the field for good. He was 19-of-25 for 219 yards and one touchdown.
Graunke completed his first nine passes for 246 yards and finished the night 9-of-11. He connected with a streaking Jason Rivers on a 72-yard pass play to put Hawaii up 52-27. Rivers had seven catches for 130 yards.
Graunke also threw a shovel pass to David Farmer, who rumbled 20 yards for a score, and completed an arching 36-yard TD pass to a diving C.J. Hawthorne to give Hawaii a 38-20 lead. Hawthorne led Hawaii with nine catches for 116 yards.