Michael Dyer's one-yard touchdown run with 30 38 ever meeting between the schools from Jordan-Hare Stadium.
"Obviously, any time you can get a win no matter how you can get it you have to be pleased with that," said Auburn head coach Gene Chizik. "I was pleased with a very young team being able to fight through a lot of adversity and persevere through times that didn't look very good to be honest. That is really good to see in our young guys. I think again that has kind of been instilled in this group that you never look at the clock and the scoreboard until it says 0:00."
Barrett Trotter threw for 261 yards and three scores on 17-of-23 efficiency for the Tigers (1-0), who trailed 21-7 in the first half and stared down a 10-point deficit inside the final four minutes but rallied to post their 16th straight win.
Dyer finished with two TDs and 57 yards rushing, while Emory Blake, Travante Stallworth and Philip Lutzenkirchen all notched a touchdown reception.
True freshman Chuckie Keeton finished with 213 yards passing and added two rushing scores for the Aggies (0-1), who fought valiantly in an attempt to beat a ranked school for the first time in 20 years, but nonetheless fell to 1-54 all-time against Top 25 teams.
"Chuckie is a special player. His fortitude, competiveness and toughness -- you saw it," said Utah State head coach Gary Anderson. "You saw exactly how he played. I think we are in very good hands at the quarterback position just as we felt as we continued through camp."
Robert Turbin posted 70 yards and a pair of rushing touchdown on 22 carries, while Kerwynn Williams added 69 yards and another score on the ground in defeat.
Ahead by three in the fourth, Stanley Morrison broke off a 30-yard run to the Tigers' 24. The Aggies then had a 4th-and-3 from the five. After a delay-of- game call, Josh Thompson lined up for a 28-yard field goal, but a fake resulted in a Morrison pass to D.J. Tialavea for a first down at the two. The initial ruling on the play was a catch, and though some replays indicated the ball hit the ground, the reception was upheld by review.
Two plays later, Turbin punched it in from the one and the Aggies went up 38-28 with 3:38 remaining.
Auburn worked quickly, taking just 91 seconds off the clock and needed just six plays to move 65 yards and climb within 38-35 as Trotter hit Lutzenkirchen in the end zone for a 15-yard TD.
The Tigers then recovered the onside kick at its own 44, and Trotter hit Stallworth, Onterio McCalebb and Lutzenkirchen during the series -- the latter pass getting Auburn down to the Aggies' 17. McCalebb then rushed for 14 and two yards before Dyer rolled under a pile and slid in from the one, a score upheld on review.
Keeton was sacked, completed a 12-yard pass to Turbin then threw an incompletion before a 33-yard connection to Michael Smith came as time expired.
Utah State grabbed the early lead after Williams broke up the middle for a 43- yard touchdown run, but Auburn equalized on the following drive as Blake took a Trotter pass and rolled 56 yards to the end zone.
Keeton put the visitors ahead 14-7 late in the first on a three-yard run on 4th-and-goal.
Turbin then capped a 16-play drive with a one-yard plunge and the Aggies led 21-7 with just under eight minutes to play in the half, but Tre Mason returned the kickoff 97 yards to make it a seven-point contest.
On the first series of the third quarter, Dyer took a direct snap on a 3rd- and-3 and pulled Auburn even with an 11-yard dash up the middle to cap an 11- play drive.
A 34-yard make from Thompson with under five minutes left in the third put the Aggies back on top 24-21, but the Tigers responded on the ensuing drive to take the lead for the first time as Trotter found Stallworth near the left sideline and he rumbled 39 yards for a 28-24 advantage.
Early in the fourth, Turbin converted a 3rd-and-inches deep in Auburn territory, then two plays later Keeton managed to extend the ball over the goal line on a seven-yard dash and Utah State led 31-28.
"No question about it, I think it is obvious that we did not play well as a football team," Chizik offered as a critique. "There are no excuses for that. I think it was very evident that our most experienced part of our football team is our special teams. I don't think there is any question that offensively and defensively we are a long way off from being able to win very many games right now."
The last defending champion to lose its season opener was Michigan, in 1998, at Notre Dame...Blake ended with 95 yards on three receptions, Stallworth tallied four grabs for 93 yards and McCalebb went for 44 yards rushing and 43 yards receiving...In defeat, the Aggies outgained the Tigers by a 448-364 margin...Utah State fell to 0-44 all-time on the road against ranked opponents, and extended its losing streak to 30 straight contests against ranked teams since a 20-19 win over Fresno State in 1991...The Aggies, who have not beaten an SEC foe since 1970, have dropped 14 straight openers overall.