Love had 19 points and 10 rebounds for his 20th double-double in the first postseason meeting between crosstown rivals who've played 225 other times. They split in the regular season.
The Bruins (30-3) won their ninth in a row and advanced to Saturday's championship game, where they will play either second-seeded Stanford or third-seeded Washington State.
Freshman O.J. Mayo led the fourth-seeded Trojans (21-11) with 15 points. Freshman Davon Jefferson added 12 points.
Mayo rallied the Trojans over the final 4 minutes, scoring seven in a row to close to 54-52. He fouled Darren Collison, who made one of two free throws to keep UCLA ahead 55-52 with 1:26 remaining.
Daniel Hackett got fouled, made both and USC drew within a point with 31.6 seconds left. The Trojans were forced to foul Collison, who made both for a 57-54 lead.
Mayo dribbled the clock down until putting up the potential game-tying 3-pointer over Josh Shipp with 2 seconds to go. It missed and Hackett rebounded, but couldn't get a shot off before time expired.
The Bruins overcame the loss of Luc Richard Mbah a Moute, who sprained his left ankle after coming down on Jefferson's foot with 6:11 remaining in the first half.
X-rays were negative and Mbah a Moute was on crutches, not a welcome sight for the junior who backs up Love on the boards. He had three points and one rebound in his short stint.
The Bruins trailed by four when Mbah a Moute went down and they closed within six at halftime.
They came out of the break a determined bunch. UCLA outscored USC 15-2 to start the final 20 minutes and take a 43-36 lead, the Bruins' first since early in the game.
