TUCSON, Ariz. (AP) -- O.J. Mayo scored 20 points and USC withstood an Arizona comeback to hand the Wildcats their fifth home loss of the season, 70-58, on Thursday night.
In a matchup of two of the game's best freshmen, Mayo got the better of Arizona's Jerryd Bayless, who matched his season low of eight points, 13 below his season average. The Wildcats' other top scorer, Chase Budinger, scored only seven points.
Davon Jefferson had 15 points and 14 rebounds and 14 rebounds for the Trojans (18-9, 9-6 Pac-10), who never trailed and led by as many as 16 in the first half. Taj Gibson added 14 points and Dwight Lewis 11.
The loss was a setback in the Wildcats' (17-11, 7-8) bid for their 24th consecutive NCAA tournament berth, the longest active streak in major college basketball and second-longest ever behind North Carolina's 27.
With 16.5 seconds left in the game, someone in the Wildcats student section threw a full water bottle at the USC bench. Arizona interim coach Kevin O'Neill took the arena microphone to admonish the perpetrator and apologize to USC coach Tim Floyd.
USC, which lost at home to the Wildcats earlier this season, shot out to an 11-2 lead and stretched it to 24-12 on Angelo Johnson's 3-pointer from the corner with 10:07 left in the half.
Jefferson scored the last four in a 15-6 USC run that made it 32-16 after his dunk 6:14 before the break.
But, with Bayless on the bench with three fouls, the Wildcats finally got things going, scoring the next 10 to cut it to 32-26 on McClellan's 3-pointer with 2:18 remaining until halftime.
USC scored the next seven, then Budinger's 10-footer made it 37-28 Trojans at the break.
Arizona chipped away at the lead, cutting it to 51-48 with 8:10 remaining when Hill blocked Lewis' shot, leading to a breakaway dunk by Bayless, who was fouled for a three-point play.
But the Wildcats never got any closer. Gibson made one of two free throws, then Daniel Hackett sank a 3-pointer from the corner to boost it to 55-48 6:56 from the finish. Fendi Onobun's dunk cut the lead to 56-52, but Mayo made two free throws, then scored on a drive and USC led 60-52 with 5:05 to play.