Junior guard Donte Smith thought he had an open fast break layup and an opportunity to close UCLA’s eight-point lead. Instead, Smith found himself stumbling to the ground with a little more than four minutes to go.

The Bruins’ Lazeric Jones had chased him down and cleanly rejected the shot. Jones stuffed the ball back into Smith’s hands, knocking Smith off-balance and sending him hurtling toward the hardwood.

That’s the type of night it was for USC and its guards as they fell 64-50 to crosstown rival UCLA (15-7, 7-3).

Despite 32 combined points from junior forward Nikola Vucevic and senior center Alex Stepheson, the Bruins controlled the game throughout. While Vucevic and Stepheson had success in the post, the Trojans had not perimeter game.

The Trojans’ (12-11, 4-6) starting guards managed only seven points. USC’s second-leading scorer junior guard Jio Fontan was held scoreless for the second time in three games. He had not been previously held scoreless in his college career.

USC managed only 15 second half points and didn’t have a single perimeter point in the final 25 minutes of play. As a team, the Trojans made only four jump shots in the game.

“We only had five turnovers,” said USC coach Kevin O’Neill. “But we didn’t make enough [shots] and they made them.”

As a team, the Bruins shot 48 percent while, on the opposite end of the spectrum, USC made only seven field goals in the second half, shooting 30 percent after halftime.

USC showed some life at the end of the first half, finishing on a 9-2 run, punctuated by a Maurice Jones drive and dish to Vucevic for an emphatic slam just before the first half buzzer expired. The run trimmed the lead down to a one-point at halftime after the Bruins had led by nine.

However, Vucevic scored only six of his game-high 18 in the second half.

Just like the first crosstown showdown this season, UCLA entered on a hot streak having won five of six. But unlike last month’s game, the Bruins assured themselves a victory by jumping out to an early lead with a 12-4 run after Stepheson scored the first two points of the game. UCLA would not trail again.

Freshman center Joshua Smith came off the bench to lead UCLA with 15 points on 5-of-9 shooting. He also collected six rebounds.

“Josh gave us big minutes off the bench and also provided us great offense,” said UCLA coach Ben Howland. “We’re starting to see glimpses of what he’s capable of.”

Wit his presence in the lineup, UCLA closed the game on a 16-5 run.

The Trojans have a week to lick their wounds before hosting the Oregon schools.

“We have to approach it now like it’s an eight-game season going into the conference tournament,” O’Neill said.

The Trojans ‘eight-game season will begin next Thursday at 8 p.m. when they play Oregon State at the Galen Center.