The Golden Bears (18-9, 9-5) trailed 30-27 after an up-and-down first half in which they led by as much as five points and trailed by as many as six.
USC hung around and went up 56-53 on a J.T. Terrell jumper with 8:14 remaining. The Golden Bears answered with 11 straight points, taking a 64-56 advantage on a pair of free throws by Kreklow with 4:18 to go.
Then Bird buried a pair of 3s, the second one putting the Golden Bears up 12 with 2:32 left.
Cobbs scored 22 points on 8-of-10 shooting after going 4-for-20 in Cal’s previous two games. He also dished out seven assists. Kreklow tossed in 12 points, while Wallace and Bird each scored 10. David Kravish grabbed 10 rebounds and blocked five shots and Richard Solomon had three steals.
Pe’Shon Howard had 17 points and four assists for the Trojans, Nikola Jovanovic and Terrell each scored 14 points, with Jovanovich also getting six boards, and Julian Jacobs finished with 10 points and six rebounds. Omar Oraby and D.J. Haley each blocked three shots.
USC was 23-for-53 (43.4 percent) overall, 4-for-11 (36.4 percent) from deep and 14-for-19 (73.7 percent) from the line. Cal was 29-for-60 (48.3 percent), 5-for-12 (41.7 percent) and 14-for-19 (73.7 percent).
The Golden Bears had a 35-31 edge on the glass and had nine turnovers, while the Trojans committed 14 giveaways.
Cal begins its final road trip of the regular season on Wednesday, visiting No. 4 Arizona at 6 p.m. Pacific.