UCLA sophomore Chance Myers scored the game's only goal in the 88th minute when he beat former Bruin Eric Conner in the Dons' goal after Kyle Nakazawa's free kick into the penalty area wasn't cleared.
The UCLA-USF rivalry dates back 40 years, and while the Dons, winners of five national championship titles (1966, 1975, 1976, 1978 & 1980), dominated the series in the early years, UCLA has had the edge recently.
The No. 5 Bruins have not lost to USF in 11 matches since dropping a 2-1 decision at San Francisco in 1993. USF, ranked No. 12 nationally, went Thursday night's game with a four-game winning streak, but U.S. U-20 goalie Brian Perk and the backline of Mike Zaher, Brandon Owens, Greg Folk and Tony Beltran shut down the Dons.
The Bruins had two other scoring opportunities earlier in second half. Zaher took a hard shot that Conner had to make a big save on, and Maxwell Griffin's shot after a Nakazawa corner kick hit the underside of the crossbar.
The win was the third in a row for UCLA, ranked No. 1 in the Soccer America Preseason Top 25, after opening 0-2-1.
"I am pleased with the way we competed tonight. We played an outstanding team tough for 90 minutes," USF head coach Erik Visser said. "To see the way they [UCLA] celebrated after the match that made me feel good. It shows we earned their respect and that we are on the right track."
Sept. 20 in San Francisco
San Francisco 0 UCLA 1. Goal: Myers 88.
San Francisco -- Conner, Rodd, Schlumpf, Cortez, Warren, Henderson, McDonald, Burke, McMullen, Russell, Chinn. Subs: Attar, Keyes.
UCLA -- Perk, Beltran, Zaher, Owens, Folk, Myers, Suits, Stephens, Leopoldo, Nakazawa, Griffin. Subs: Flores, Konowiecki, Sinderhoff, Jaramillo.
Referee: Tim Weyland.