Tim Lincecum lost his fifth straight start, and Barry Enright and two relievers combined on a seven-hit shutout for the Arizona Diamondbacks in a 6-0 win over the San Francisco Giants on Friday night.
Lincecum has never lost five starts in a row before. His ERA in August is 7.82.
The winner of the last two NL Cy Young awards, Lincecum gave up four runs on five hits in six innings.
Adam LaRoche homered, and Stephen Drew doubled, tripled and scored three times for Arizona, which snapped a seven-game losing streak to San Francisco.
The loss dropped San Francisco one-half game behind Philadelphia in the NL wild card race.
The Diamondbacks entered the night with the third-worst record in baseball and had lost nine of their previous 13 games before jumping on Lincecum and the Giants early.
LaRoche provided the big blow with a three-run homer off Lincecum in the first inning, his 22nd of the year. LaRoche is batting .326 with eight home runs in August and needs six RBIs to break the franchise record for first basemen.
Lincecum (11-9) has tried just about everything to break his slump but hasn't had much luck.
The right-hander wore striped stirrups for the first time this season but opened the game with a four-pitch walk to Drew. He struck out the next two batters then walked Chris Young before LaRoche homered on a 1-2 pitch into McCovey Cove.
The Diamondbacks tacked on another run off Lincecum in the third when Drew tripled and scored on Justin Upton's sacrifice fly.
Since opening the season 5-0 with a 1.76 ERA, Lincecum has struggled more than at any other time in his career. He hasn't won since July 30 and is 6-9 with a 4.80 ERA over his last 19 starts.
While Lincecum was struggling, Enright was stellar in his second start against the Giants this season.
The rookie right-hander pitched out of a two-on, one-out jam in the third and got plenty of backing from Arizona's defense. The Diamondbacks turned a 3-6-1 double play in the second and left fielder Gerardo Parra made a diving catch on Pat Burrell's sinking line drive in the fourth.
San Francisco put two runners on base again in the fifth but Enright (5-2) struck out Buster Posey.
Enright scattered six hits over seven innings with four strikeouts and two walks for Arizona, which had lost six straight at AT&T Park.
Blaine Boyer pitched the eighth and D.J. Carrasco recorded the final three outs for the Diamondbacks.
Arizona scored twice in the ninth on Kelly Johnson's second double of the night. Johnson finished 3 for 5.
Notes: Enright has pitched at least five innings and allowed fewer than three runs in each of his 11 starts this season. ... LaRoche's homer off Lincecum is the second time he's homered into McCovey Cove off the Giants' ace. ... The Giants lost for the second time in 11 games while wearing their orange jerseys this season. ... San Francisco 2B Freddy Sanchez was charged with an error in the ninth inning when he bobbled pinch-hitter Ryan Roberts' grounder. It's Sanchez's first error since Sept. 19, 2009. ... Sanchez is 11 for 15 over his last four games.