SAN DIEGO — The Shootout at Qualcomm Stadium during the U.S. Navy's Fleet Week did without one of its participants: BYU. The Cougars went missing in action Saturday night before a crowd of 41,680 and host San Diego State notched an easy 31-10 victory.

San Diego State quarterback Kevin O'Connell teamed with halfback Lynell Hamilton and receiver Jeff Webb to chase BYU's defense all over the field, scoring four rushing touchdowns for the first time in four years.

The Cougar offense couldn't help out its brethren. It had no lifeline in the Cougars' first night and first road game. BYU was flat as a week-old bottle of Sprite.

The Aztecs (2-3, 1-1) looked as good as the Cougars (1-3, 0-2) danced ugly. The win lifted SDSU to its first league victory, while BYU now travels to Albuquerque still searching for its. It was BYU's first loss to SDSU here in 17 years — eight straight trips.

"It's not easy to have a team sit in the shotgun and throw 50 passes like they do. We never lost our focus," SDSU coach Tom Craft said. "We controlled the ball. They dropped some passes, we pressured their receivers, and their quarterback had an accuracy problem."

Craft said SDSU changed its defense for BYU but wouldn't elaborate.

Fresh off a 51-point, 614-yard offensive performance where BYU defenders flamed out at the end of an overtime loss to TCU a week earlier, the Cougar offense came out without a torch here, and the Aztecs made hay. BYU looked tired and uninspired. In other circles, you could say BYU looked hung over from the downer a weekend ago.

This was never more apparent than with Cougar quarterback John Beck. After a record-setting 517-yard passing performance against TCU, in this follow-up he misfired early and often. Trailing 17-3 at the half, the Cougars got the ball after halftime, and Beck promptly fumbled a pass attempt at BYU's 32. He simply lost the handle without being touched.

That turnover, Beck's second in five plays, set up Aztec Brandon Bornes' 7-yard touchdown run and a 24-3 lead minutes into the second half.

It's debatable how much of it was Beck & Co. failure or Aztec solid defensive coverage, consistent pressure and production of drive-stopping plays.

You could make a case for both.

SDSU outgained BYU 508 to 305 in total yards and had a 26-15 advantage in first downs. SDSU's work was equal, with 265 yards rushing and 243 through the air.

The Cougars managed 44 rushing and 261 by pass. Beck finished 25-of-49 with two picks.

Trailing 24-3 in the fourth quarter, the Cougars' best effort offensively came on a fourth-and-9 at midfield when Beck hit Johnny Harline for a 35-yard gain at the Aztec 7. Three plays later, three quarters gone in the game, Fahu Tahi ran in standing up from the 2 to cut SDSU's lead to 24-10. A later Cougar drive to SDSU's 6 died on downs, with a Beck pass off his back foot sailing past Harline in the end zone.

But SDSU answered when Hamilton ripped off a 57-yard run to BYU's 20 where the Aztecs padded the lead to 31-10 on a 4-yard Hamilton run, his 144th yard gained in the game, capping a 90-yard drive.

With starting defensive linemen Manaia Brown back in Provo with a concussion and Vince Feula (ankle) out, linebackers Cameron Jensen and Paul Walkenhorst were also sidelined. Nose guard Daniel Marquardt didn't start but played significant time with broken ribs.

Mendenhall started Justin Maddux, T.J. Sitake and Halo Poanga on the D-line and put Aaron Wagner and Markell Staffieri at linebacker spots. Corners Justin Robinson (ankle) and Nate Soelberg (knee) started after missing practices during the week.

Here's how BYU never got started: The Aztecs moved the ball consistently on the Cougars in the first 22 minutes and scored on a Kevin O'Connell quarterback keeper from the 6 with 8:57 left in the second quarter to take a 7-0 lead.

O'Connell gave the Cougar defense fits, consistently taking advantage of BYU's soft cover on the corners on big third-down plays. O'Connell completed his first 11 passes, leading up to that first Aztec touchdown. The big SDSU plays on that 80-yard, 13-play drive included third-down conversion passes of 16 yards to Chazeray Schilens and seven yards to Jeff Webb.

When running back Hamilton scampered 26 yards on a first-and-10 at BYU's 39, it was easy picks for the Aztec offense.

Meanwhile, BYU's offense, which started the game with a scoreless 14-play possession, couldn't mount any kind of rhythm. Beck was 5-of-11 at that stage, and when the Cougars punted, Craft decided to go after the Cougar secondary with a seven-point lead on something other than third downs.

O'Connell launched a 50-yard bomb to Webb, who had Soelberg beat, and Robinson made a TD-saving tackle at the Cougar 12. BYU's defense held up, preventing a touchdown, but the Aztecs zipped ahead 10-0 on a Garrett Palmer 30-yard field goal with 5:54 to play in the first half.

Where the Cougars had 24 points at home on TCU at that stage of the game, they appeared tentative, uncertain and unable to make plays against Aztec defenders in the first half. Beck couldn't hook up with Tahi on a short pass on first down on the next Cougar possession and after a 5-yard sack Beck missed Harline deep. He started the game 5-for-12 and it got worse.

Cougar linebacker Bryan Kehl's recovery of a muffed punt catch on the next play gave the Cougar offense its deepest penetration of the first half at SDSU's 40. That play sparked the offense for about a minute.

Beck missed Zac Collie on a 15-yard try. Brown ran for 6, and on third-and-4 at the 34 Beck caught then hit Tahi in stride for a catch-and-run to the Aztec 7 on a 27-yard play, the longest Cougar play of the first half.

But even with a first-and-goal inside SDSU's 8, the Cougars couldn't get a touchdown.

SDSU sacked Beck for a loss of nine on a bootleg action play. Beck tossed the ball away on the next play when SDSU had the coverage, and on third down threw the ball over the head of Todd Watkins at the goal line — the ball sailing out of the end zone back line. Beck was 6-for-18.

Jared McLaughlin put the Cougars on the board with a 40-yard field goal with 2:49 to play in the first half. The Aztecs led 10-3.

But SDSU was in command. BYU's offense was AWOL The Aztecs quickly took advantage of BYU's tiring defense, marching 76 yards in 15 plays to score on a 1-yard Hamilton plunge to lead 17-3 at the half. O'Connell ripped off a 21-yard keeper to ignite that drive.

Beck, 9-for-22 for 90 yards in the first half, went into intermission throwing an interception to an Aztec safety at the SDSU 15. No Cougar receiver could be spotted within 15 yards.

Webb, who lit up BYU's defense in 2003 here with 10 catches for 253 yards and three touchdowns (he had 706 yards receiving all season), had 10 receptions for 105 yards at halftime. At that stage, SDSU tripled the offensive output on BYU (310 to 100 yards). Webb ended the game with 13 catches for 129 yards.