Zito (7-15) allowed five hits in seven innings, struck out three and walked two, combining with Keiichi Yabu and Sergio Romo on a seven-hitter. Zito pitched out of trouble, stranding two runners each in the third, fifth and seventh innings.
The major league leader in losses, Zito has won just 18 of 58 starts since signing a $126 million, seven-year contract with San Francisco before the 2007 season.
He improved to 97-5 in his career when receiving four or more runs of support, including 12-1 with the Giants. San Francisco has scored one run or none in 24 of his starts.
San Francisco pitched its ninth shutout, one shy of the Los Angeles Dodgers, the NL leader. Aaron Rowand homered and drove in two runs for the Giants.
Atlanta has lost six of seven and was outscored 47-22 during a seven-game homestand. The Braves were hurt by poor hitting with runners in scoring position, with Chipper Jones' popout ending the third, Mark Kotsay hitting into an inning-ending forceout in the fifth and Yunel Escobar hitting into a forceout that ended the seventh.
Jorge Campillo (7-6) gave up five runs and seven hits in 6 2-3 innings.
Rowand hit a sacrifice fly in the first after Dave Roberts' triple, and Rich Aurilia and Pablo Sandoval followed with RBI singles.
Rowand's homer made it 4-0 in the sixth. San Francisco scored another run in the seventh when Campillo loaded the bases by bouncing ball four to Roberts and catcher Brian McCann, apparently losing track of the count, threw the ball into left field for an error as Emmanuel Burriss sprinted to third.
Notes: Braves LHP Tom Glavine has an appointment Wednesday to be have his left elbow examined by Dr. James Andrews in Birmingham, Ala. ... Braves manager Bobby Cox said LHP Jo-Jo Reyes will be brought up Tuesday from Triple-A Richmond to take Glavine's turn in the rotation at the New York Mets. ... Giants RHP Kevin Correia, who faces Florida in San Francisco on Tuesday, is 0-1 with a 7.65 ERA in two starts and seven relief appearances against the Marlins.