Zito, Giants close gap with Cards in shutout

San Francisco Giants' Pablo Sandoval hits a home run during the eighth inning of Game 5 of baseball's National League championship series against the St. Louis Cardinals, Friday, Oct. 19, 2012, in St. Louis. (AP Photo/David J. Phillip)

ST. LOUIS — Barry Zito pitched the San Francisco Giants back into the NL championship series, dominating into the eighth inning of a 5-0 victory over the St. Louis Cardinals on Friday night that narrowed their deficit to 3-2.

The defending champion Cardinals might have thrown away a chance to clinch a second straight World Series trip. Pitcher Lance Lynn’s toss on a possible forceout deflected off the second-base bag, paving the way for the Giants’ four-run fourth.

Pablo Sandoval homered for the second straight night and Zito made an extremely rare offensive contribution with a perfectly executed bunt for an RBI single.

The Giants’ win in Game 5 sent the series back to San Francisco. Game 6 will be Sunday (7:45 p.m., WTAT-TV) at AT&T Park, with Ryan Vogelsong pitching against the Cardinals’ Chris Carpenter. Game 7, if necessary, would be Monday night.

Once again this postseason, the Giants benefited from a big error.

Needing three straight wins at Cincinnati to avoid elimination in the division series, San Francisco began its comeback on a bobble by third baseman Scott Rolen in the 10th that gave the Giants the go-ahead run in Game 3.

The Giants improved to 4-2 on the road this postseason and have won Zito’s last 13 starts, with the last setback on Aug. 2. They’re averaging more than six runs a game during the streak, although the lefty didn’t need much help in this one.

Zito looked like the same guy who won the 2002 AL Cy Young award. He retired 11 batters in a row in one stretch while scattering six hits with six strikeouts in 72/3 innings.

Giants catcher Buster Posey twice tapped Zito on the chest when he was pulled in the eighth inning. It was Zito’s first postseason win since 2006, shortly before he left the A’s and signed a $126 million, seven-year contract with San Francisco.

Zito was left off the postseason roster when the Giants won the 2010 World Series because he had pitched so ineffectively. He started Game 4 of the division series against the Reds earlier in this year’s playoffs and lasted only 22/3 innings.

Lynn, an 18-game winner his first year in the rotation, failed to make it out of the fourth for the second time in the series.

The Cardinals are seeking consecutive pennants for the first time since 1967-68, and trying to advance for the second year in a row as a wild-card entry. One more win would set up a rematch of the 2006 World Series against the Tigers, which the Cardinals took in five games.

Zito’s only trouble came in the second when Yadier Molina and David Freese, both swinging on the first pitch, opened the inning with a single and double. Lynn, a career .056 hitter including the postseason, hit into a bases-loaded double play to end the threat.

Lynn was 3 for 50 with 1 RBI, 10 sacrifices and 36 strikeouts during the regular season, going hitless his last 42 at-bats.

NOTES: Standing room attendance for Game 5 was 47,075, a franchise best for league championship play, topping the previous best in Game 4 by 13. ... Actor Matthew Morrison sang the national anthem. ... Longtime Cardinals broadcaster Mike Shannon bounced a ceremonial first pitch from in front of the mound to Lou Brock, teammates on the last St. Louis team to go to consecutive World Series in 1967 and `68. ... Carlos Beltran has 10 career stolen bases in the postseason. ... Matt Carpenter, who subbed for Beltran in Games 3 and 4, is a career .529 hitter (9 for 17) against the Giants counting the postseason with a homer and four RBIs. ... Cardinals rookie RHP Trevor Rosenthal struck out four in two scoreless innings. He has fanned 11 in 6 2-3 scoreless innings in the postseason while allowing just one hit.