The teams, vying for third place in the tournament, played close for the first few minutes, until SDSU (4-2) built a 13-point lead with just under six minutes left in the half.
Lamont Butler paced No. 17 SDSU, scoring nine as the Aztecs took a nine-point lead into the half. But his late mistakes doomed them.
The Razorbacks cut the lead to three after a bad pass by Darrion Trammell and a three-point shot by Trevon Brazile, but San Diego State battled back. The advantage grew again to 11, thanks to a Matt Bradley layup with 14:27 to play.
SDSU, however, could not put Arkansas away, Even so, the Aztecs held on to a four-point lead with 17 seconds to play, following two free throws by Adam Seiko. With 13 seconds left, though, Butler inexplicably reached in to foul Anthony Black, who made both free throws.
Six seconds later, Butler, double teamed, could not hold on to the ball, and Brazile grabbed it. After a timeout, Black missed a layup, but Kamani Johnson grabbed the offensive rebound and put it in the basket at the buzzer to force the OT.
“But obviously, we can’t turn it over and that’s what happened,” head coach Brian Dutcher said.
Arkansas took their first lead since early in the first half with a layup by Ricky Council to begin in OT. SDSU answered with a three by Trammell to go up again 70-69, but that would be the Aztecs’ final lead of the game, with 3:58 to play.
Down 76-74 with five seconds left, Bradley had a chance to tie it up with a layup, but the ball slipped along the back of the rim and and fell to the floor. The senior lay on the court with his head in his hands after the miss.
The Aztecs and Razorbacks met for the third time ever and the first time in more than 35 years – Arkansas won 76-64 on Dec. 3, 1985 in Fayetteville. With Wednesday’s loss, San Diego State fell to 0-4 in the series.
No. 14 Arizona continued to be hot, following the Wildcats’ convincing 87-70 Tuesday win over the Aztecs, defeating No. 10 Creighton 81-79 in Wednesday’s marquee game.
SDSU resumes play at 7 p.m. Tuesday when they host UC Irvine at Viejas Arena.