Top-ranked Arizona suffered its first loss of the season, falling 60-58 Saturday night at California.
Justin Cobbs hit a fadeaway jumper with 0.9 seconds left for Cal (15-7, 6-3 Pac-12), which held for the final shot after forcing a bad attempt by Arizona (21-1, 8-1) with 15 seconds remaining.
Arizona played most of the game without second-leading scorer Brandon Ashley, who suffered a foot injury early and did not return. Cal dominated inside for a while after that, leading 24-17 in the first half, before Arizona pulled within 30-29 at the half.
The Wildcats rallied in the second half behind stellar rebounding, a perfect night from the free-throw line and 19 points from Kaleb Tarczewski.
Cobbs had a game-high 19 points for Cal, which beat a No. 1 team for the first time since 1994.