ST. LOUIS — Madison Bumgarner set a major league record and gave the San Francisco Giants an arm up in the National League Championship Series.

Throwing 7⅔ scoreless innings Saturday night, Bumgarner led San Francisco to a 3-0 win over the St. Louis Cardinals at Busch Stadium and a 1-0 lead in the best-of-seven series.

The left-hander allowed only four hits, none for extra bases, and walked one while fanning seven. Dating back to the fifth inning of Game 6 of the 2010 NLCS against Philadelphia, Bumgarner has pitched 26⅔ straight scoreless innings, breaking a 90-year-old record held by Art Nehf of the New York Giants (1921-24).

St. Louis came closest to scoring in the seventh, but Bumgarner whiffed pinch-hitter Tony Cruz with runners at second and third for the inning’s third out.

Sergio Romo got the last out of the eighth and closer Santiago Casilla pitched the ninth for his third postseason save. The Giants improved to 4-0 on the road in this postseason.

Adam Wainwright took the loss for St. Louis, failing to complete the fifth inning for his second straight postseason start. The Cardinals will try to even the series Sunday night when right-hander Lance Lynn faces veteran Jake Peavy.

Left fielder Travis Ishikawa collected two singles and an RBI for San Francisco, which won despite stranding 10 men on base, six in scoring position.

San Francisco broke the scoring seal with two runs in the top of the second. Ishikawa blooped a bases-loaded RBI single into short left field to plate third baseman Pablo Sandoval.

Center fielder Gregor Blanco reached on a two-out error by third baseman Matt Carpenter, which scored right fielder Hunter Pence.

First baseman Brandon Belt upped the Giants’ lead to 3-0 in the third with a sacrifice fly to center that scored catcher Buster Posey.

Adam Wainwright lasted just 4⅔ innings, departing after walking Belt. Wainwright gave up six hits and three runs, two of which were earned, while walking three and striking out two.

NOTES: San Francisco OF Michael Morse (left oblique) was activated for the NLCS, although he wasn’t in the Game 1 starting lineup. Morse missed 23 of the Giants’ last 24 regular-season games after being injured during batting practice Sept. 1 in Colorado. … St. Louis opted to go with 14 position players and 11 pitchers as the Cards activated C A.J. Pierzynski over LHP Sam Freeman, giving it a veteran bat off the bench. … This series matches the teams with the most postseason wins since 2010. The Cardinals lead all of MLB with 30 and the Giants are right behind at 26.