SAN FRANCISCO (AP) -- Joe Blanton, called into late duty to replace Clayton Kershaw, kept thinking he had the right pitch to retire Buster Posey. And Posey stayed in there each time.
Moved up a day, Blanton surrendered Posey's career-best 20th home run shortly before his rough night ended, and the Los Angeles Dodgers dropped to 5 1/2 games back of the NL West-leading Giants with a 4-0 loss to San Francisco on Sunday night.
And certainly from the Giants' perspective, they caught a big break facing Blanton instead of the reigning NL Cy Young Award winner in a game of this magnitude. Kershaw, who is 5-2 with a 0.66 ERA at AT&T Park, had a cortisone shot for an inflamed right hip joint Saturday.
Los Angeles (74-67) dropped 1 1/2 games back of St. Louis for the second NL wild card with a crucial four-game set against the Cardinals starting Thursday at Dodger Stadium. Atlanta leads the wild card by 5 1/2 games.
"I'm not worried about our chances," Shane Victorino said. "I've been in worse. I've been eight back with 17 to go and won a division."
Manager Don Mattingly knows his team must produce more timely hits the rest of the way to stay in the mix. They failed to deliver with runners in scoring position all series.
"It's hard to sit here and say I feel great because we haven't played that well," Mattingly said. "It stings us because it's a two-game swing with our trying to catch these guys. It changes from 3 1/2 to 5 1/2. We're at a time where you feel like you have to win every day."
Barry Zito delivered on one of the biggest stages yet during six up-and-down years in San Francisco.
"This game's obviously bigger because not only is it against our rival in the West, it's the Dodgers, too," Zito said. "Being 5 1/2 up, we like where we're at. We certainly can't rest on our laurels. We have to fight every day, and that's something we've been doing all year."
Hunter Pence hit a two-run double in the first inning that held up and Posey homered in San Francisco's fifth win in the last six meetings of the rivalry.
Posey connected in a 10-pitch at-bat featuring six fouls against Blanton (1-4) to start the sixth.
"That's one of the best at-bats I've ever had off of me," Blanton said. "I threw him at least five put-away pitches, I thought, and he just kept fouling them off."
Marco Scutaro added a sacrifice fly to back an impressive performance by Zito (11-8), who drew loud cheers all night from the orange flag-waving sellout crowd of 41,517. Zito, left off the postseason roster for all three rounds during the team's 2010 World Series title run, also matched a season high for wins since joining the Giants on a $126 million, seven-year contract before the 2007 season. He also had 11 in '07.
San Francisco earned its NL-leading 13th shutout and fourth against the Dodgers. The Giants swept Los Angeles at AT&T Park from June 25-27 by scores of 8-0, 2-0 and 3-0. Zito and five relievers combined on Sunday's five-hit shutout.
The Dodgers scratched Kershaw a few hours before first pitch -- and he wasn't happy with the decision by Mattingly, saying, "I would have loved to pitch today." The lefty (12-7) is now scheduled to start Tuesday at Arizona following an off day for the club Monday.
"It definitely affected me. I didn't want to face him," Zito said about missing Kershaw.
Blanton was told Saturday there was a "50-50 chance" he might be called upon to start in Kershaw's place. He needed 36 pitches to get out of the first, giving up as many runs that inning as Kershaw did total in any of his four starts facing San Francisco this year.
Angel Pagan matched his career high with an 11th triple, leaving him one shy of the San Francisco record. Hall of Famer Willie Mays hit 12 in 1960 and Steve Finley did so in 2006.
The Giants have all the momentum in the West -- and hope to leave little to chance in the season's final week, when they end the year with three games at Dodger Stadium from Oct. 1-3.
"It would definitely be a little easier for us than to give them any chance of hope that they may have," reliever Sergio Romo said. "They've got to be able feed off it. For us to go in there and not have to worry about it, that would be huge for us."
Los Angeles is searching for timely hits after going 1 for 23 with runners in scoring position for the series.
"What I see is I see the same lefties getting us out all the time," Mattingly said.
The left-hander -- pitching to chants of "Zito! Zito!" -- worked into the seventh inning and gave the Giants only their second home series win since being swept at home by the Dodgers on July 29.
Zito allowed four hits, struck out four and walked three in 6 1-3 scoreless innings to win his third straight decision. But it was just his third victory over the last seven starts and followed a pair of no-decisions by the 2002 AL Cy Young Award winner.
Zito left to a standing ovation when he gave way to Santiago Casilla with one out in the seventh and runners on first and second following a walk to A.J. Ellis. The pitcher raised his glove to acknowledge the fans.
Casilla entered and retired pinch-hitter Bobby Abreu on a called third strike, then walked Mark Ellis before Victorino left the bases loaded with a flyball to left.
"That's the frustrating part, that's the part that makes you want to go bang your head against the wall," Andre Ethier said of the Dodgers not coming through. "I don't know if it's pressing too hard or not caring enough."
San Francisco has won Zito's last seven outings since an Aug. 2 loss to the New York Mets.
NOTES: LHP Paco Rodriguez made his major league debut for the Dodgers. ... Zito is 10-1 this year when receiving four or more runs of support. ... Los Angeles INF Adam Kennedy expects to miss the rest of the season with a strained right groin he hurt Friday night. "It's pretty bad," he said.
