Alex Stepheson had 14 points and 16 rebounds and fourth-seeded Southern Cal recovered from a slow start to defeat fifth-seeded California, 70-56, Thursday in the quarterfinals of the Pac-10 tournament in Los Angeles.

Maurice Jones scored 16 points and Donte Smith added 14, including four 3-pointers, to lead Southern Cal (19-13), which scored on just one of its first 14 possessions and trailed 16-9 with 7:37 left in the first half.

After starting 1 of 11 from the field, USC shot 24 of 45 (53.3 percent) for the rest of the game. The Trojans will face the winner of Thursday’s Arizona-Oregon State game in Friday’s semifinals.

Allen Crabbe scored a game-high 21 points for California (17-14), which trailed by 20 midway through the second half. Richard Solomon had 11 points and six rebounds, and Brandon Smith added 10 points.

Jio Fontan had 12 points for the Trojans, who shot 8 of 17 (47.1 percent) from 3-point range. Southern Cal forward Nikola Vucevic, averaging 17.7 points and 10.3 rebounds, battled foul trouble and finished with seven points and five rebounds.

Crabbe, the Pac-10 Freshman of the Year, brought the Bears to within 10 on his 3-pointer with 6:42 remaining, but Southern Cal answered with five straight points to secure the win.