UNLV built a 14-point second-half lead, then weathered a furious rally behind Elijah Mitrou-Long's 19 points to hand No. 4-ranked San Diego State its first loss of the season, 66-63 at Viejas Arena.
The Runnin' Rebels (15-14, 10-6 Mountain West Conference) held San Diego State (26-1, 15-1) to 38.9 percent shooting from the floor, and 29.6 percent from behind the 3-point line, en route to snapping the nation's longest winning streak.
UNLV's stifling defensive effort led to a 14-point lead with just under 11 minutes remaining, but San Diego State responded by holding the Runnin' Rebels without a field goal for more than seven minutes.
Mitrou-Long, who made a variety of critical plays down the stretch, ended the dry spell with 3:01 remaining when he made a tear-drop floater. The basket gave UNLV a nine-point lead -- and the Runnin' Rebels needed just about every point.
Behind a game-high 24 points from Malachi Flynn, San Diego State chipped away at the deficit over the closing minutes. Flynn snapped one of his six assists to Aguek Arop for a lay-in with 25 seconds remaining that pulled the Aztecs to within two points.
Flynn then answered a pair of Mitrou-Long free throws with a 3-pointer to cut the UNLV deficit to one point. But on the ensuing inbound pass, Mitrou-Long bounced the ball off an unsuspecting Matt Mitchell's back, operating as his own, one-man press break to kill the clock and earn two more free throws.
Flynn missed the would-be game-tying attempt on San Diego State's next possession, and Marvin Coleman made a heads-up hustle play when he threw the ball off Arop to give UNLV the ball.
Mitchell intercepted the baseball inbound throw and heaved a desperation half-court shot at the buzzer that went just wide of the rim.
Mitchell finished with 13 points for the Aztecs. Jordan Schakel added 10 points before fouling out. Flynn grabbed nine rebounds to go with his game-highs in points and assists.
Amauri Hardy scored 17 points for UNLV. Bryce Hamilton added 11 points.
With San Diego State's loss, the 2014-15 Kentucky Wildcats remain the last team to reach the NCAA Tournament with a perfect record. The 1975-76 Indiana Hoosiers remain the last team to go undefeated to a national championship.
--Field Level Media