Cole Garvin threw for 241 yards and three touchdowns in place of injured starter Dallas Davis, and South Alabama beat No. 19 San Diego State 42-24 on Saturday night.
A sophomore who transferred from Marshall, Garvin threw touchdown passes of 37 yards to Kevin Kutchera, 79 yards to tight end Gerald Everett, and 6 yards to Josh McGee.
"We had a great week of practice," Garvin said. "I was nervous until I got on the field. I mean, I haven't played in three years. But we had a great game plan and my receivers made some great, great catches."
San Diego State's Donnel Pumphrey ran for 156 yards and a touchdown on 25 carries. He broke 100 yards rushing for the 25th time and went over 5,000 yards to become the Mountain West's career leader.
Jaguars coach Joey Jones said the plan was to keep Pumphrey hemmed in.
"Our defense believes in themselves," Jones said. "We had a plan to keep him off the perimeter and they played their tails off tonight."
It was a back and forth for most of the game, with the teams trading scores into the fourth quarter.
But after South Alabama (3-2) took a 28-24 lead on Garvin's strike to McGee in the left corner of the end zone with 11:58 left, a bad punt snap on the Aztecs' next possession set up South Alabama at the San Diego State 3 and Dami Ayola took it in from there for a 35-24 bulge.
Regular long snapper Turner Bernard went out early in the game, forcing freshman Mark Ellis into duty.
It got worse for the Aztecs (3-1) on the ensuing drive when South Alabama's Devon Earl returned a fumble 80 yards for a touchdown to seal it with 4:17 to go.
South Alabama's other score came on Tyreis Thomas' pinballing 12-yard run. On Everett's TD, he outraced the secondary the final 45 yards down the left sideline to the end zone.
San Diego State scored on Rashaad Penny's 15-yard run, Pumphrey's 7-yarder, John Baron II's field goal, a short TD pass from Christian Chapman to Kahale Warring, and a 2-point conversion throw to David Wells.
San Diego State fell to 0-2 all-time against South Alabama, and the Aztecs are now 13-6-1 against the Sun Belt Conference.
SAN DIEGO STATE: Hosts UNLV next week.
SOUTH ALABAMA: Off next week.