JJ O'Brien had a strong second half and finished with 12 points and 11 rebounds, helping No. 16 San Diego State to 53-49 victory against No. 25 Utah in a Tuesday matinee between cold-shooting teams that had a crazy final 47 seconds.

O'Brien, who played for Utah as a freshman, had no points and three rebounds in the first half, and SDSU trailed 18-17 at the break. The Aztecs looked like a different team in the second half, starting when O'Brien grabbed a rebound and then made a reverse layup 40 seconds in.

Angelo Chol scored six points during a 9-0 run that put SDSU (2-0) ahead for good.

The teams combined for 18 points in the final 46.8 seconds.

Utah pulled within three on a layup by Delon Wright and 3-pointers by Brandon Taylor and Jordan Loveridge. Aqeel Quinn made one free throw for SDSU in that span.

SDSU freshman Trey Kell then made two free throws with 16.8 seconds left to make it 51-46. It was Taylor's fifth foul that sent the point guard to the line.

Wright pump-faked Skylar Spencer from behind the 3-point line and drew a foul with 10 seconds left. He made all three free throws to pull the Utes to 51-49.

Dwayne Polee II made two free throws with 9.5 seconds left for SDSU.

SDSU won its sixth straight game against former conference rival Utah (1-1). The teams hadn't met since 2011.