The Dodgers started the day 2½ games back of the Padres in the NL West and wild-card races after missing a chance to gain ground Friday. San Diego had a night game at Colorado on Saturday.

Kevin Frandsen's one-out single to left in the sixth broke up Boomer's bid. The burly left-hander became the 14th pitcher in major league history to throw a perfect game in the regular season on May 17, 1998, a 4-0 victory over Minnesota while with the New York Yankees.

After Frandsen's base hit, the 44-year-old Wells took a deep breath and wiped his brow. Scott McClain then reached on a fielder's choice in his Giants debut and scored on an error when third baseman Shea Hillenbrand's wild throw hit McClain as he rounded second on Rajai Davis' single. Rookie Nate Schierholtz followed with his second triple in as many days, scoring Davis to make it 3-2.

Pedro Feliz doubled off the wall in center to start the seventh, but Wells retired the next three batters in order and clapped his throwing hand into his glove as he headed back to the dugout.

Wells (7-8), who signed with the Dodgers on Aug. 24 after being designated for assignment by the Padres, won for the second time in as many decisions with his new club. He struck out four and didn't walk a batter in seven innings, allowing four hits and two runs.

He didn't get a decision in his last outing Aug. 31, then began serving a seven-game suspension the next day.

Wells was suspended for his animated argument with an umpire who ejected him on July 7 against the Atlanta Braves, a scene that ended with the pitcher hurling a ball into the screen as he left the field. Wells was also fined $3,000. On Aug. 1, commissioner Bud Selig hit Wells with another $5,000 fine for criticizing the original punishment.

Barry Zito (9-12) saw his winless stretch reach four starts, but lost for the first time since Aug. 12 against Pittsburgh. Facing Los Angeles for the third time this season, Zito again fell behind early as he has so many times this season.

He gave up his 23rd-25th runs in the frame on Gonzalez's homer to deep right-center. By comparison, Zito's next-biggest inning has been the third with 15 runs allowed.

Zito allowed four hits and three runs in six innings, struck out five and walked three. Dan Giese relieved Zito in the seventh to make his major league debut, then pitched two perfect innings.

Gonzalez — who hit his 13th homer of the year and the 25th of his career versus the Giants — came into the game batting .500 (6-for-12) against Zito, who signed to a $126 million, seven-year contract last winter.

Juan Pierre's bunt single in the first gave the Dodgers' center fielder a 10-game hitting streak. He has hit in 25 of his last 26 contests.

Tony Abreu and Ramon Martinez had RBI singles and Rafael Furcal squeezed in a run in the ninth to make it 6-2.

San Francisco slugger Barry Bonds got most of the day off, striking out in the eighth against Jonathan Broxton as a pinch-hitter. Takashi Saito pitched the ninth.

San Francisco snapped an 11-game home losing streak to Los Angeles on Dan Ortmeier's walkoff homer Friday night, and Ortmeier was back in the lineup Saturday.