ST. LOUIS >> The San Francisco Giants took advantage of Lance Lynn’s throwing error in the fourth to take a 4-0 lead over the St. Louis Cardinals after six innings in Game 5 of the NL championship series Friday night.

Barry Zito and some fine defense gave the Giants a chance to send the best-of-seven series back to San Francisco. St. Louis leads 3-1.

The Cardinals are seeking to go to consecutive World Series for the first time since 1967 and 1968. The Giants have never won a postseason series when down 3-1. But they did win three games in a row — all on the road — to overcome a 2-0 deficit and beat Cincinnati in the NL divisional series.

Lynn’s start mirrored his effort in Game 1 — three strong innings followed by a messy fourth that ended his night.

Marco Scutaro and Pablo Sandoval singled to start the inning. Lynn struck out Buster Posey then got Hunter Pence to hit a high chopper near the mound. But Lynn’s throw to second hit the base and caromed into center field, scoring Scutaro.

Brandon Belt lined out but Gregor Blanco walked and No. 8 hitter Brandon Crawford singled home two runs. Zito laid down a perfect bunt single to score Blanco. All four runs were unearned.

Lynn was lifted after 3 2-3 innings. He allowed four hits, walked two and struck out six.

In Game 1, Lynn also yielded four runs in the fourth, though the Cardinals had already scored six. The St. Louis bullpen shut out San Francisco and the Cardinals won the opener 6-4.

Zito, who gave up four hits through six, escaped a big jam of his own in the second and a lesser one in the fourth. Yadier Molina led off with a single up the middle and David Freese followed with a double down the right field line — Pence just missing a catch on a diving attempt — to put runners on second and third. But Daniel Descalso struck out and, after an intentional walk to Pete Kozma, Lynn bounced into a double play. Lynn was 3 for 50 in the regular season, but hadn’t hit into a double play all year.

Allen Craig doubled to lead off the fourth but was stranded.

Three outstanding defensive plays aided Zito. In the fifth, Pence made a sliding catch of Kozma’s looper down the right field line, and Scutaro slid into the outfield grass to get pinch-hitter Shane Robinson’s grounder and nipped him at first. Angel Pagan made a running grab of Craig’s low liner to center field in the sixth.

Zito’s outing was another in quite a comeback year.

Zito is just 58-69 with a 4.47 ERA since signing a $126 million, seven-year deal with San Francisco prior to the 2007 season. He was left off the postseason roster in 2010, when the Giants won the World Series.

But the 34-year-old left-hander went 15-8 with a 4.15 ERA this year. Zito went 7-0 over his last 12 starts, including a 4-2 win at St. Louis on Aug. 7. The team won all 12 of his outings. Though Zito’s’ ERA over the span was 4.04, the Giants averaged more than six runs per game.

The stretch included the Giants’ 8-3 win in Game 4 in Cincinnati. Zito lasted just 2 2/3 innings, allowing two runs in his only other postseason appearance this season.

Lynn was a surprise All-Star after moving from the bullpen into the rotation when Chris Carpenter was lost to a nerve injury in spring training. An 18-game winner, Lynn was much better in the first half than the second. He was 11-4 with a 3.41 ERA at the All-Star break, 7-3 with a 4.32 ERA after and was briefly relegated to the bullpen.