Giants 3, Cardinals 0: Madison Bumgarner struck out seven in 7 2/3 innings and Pablo Sandoval went 3-for-4 as visiting San Francisco defeated St. Louis in the opener of the National League Championship Series.

Travis Ishikawa contributed a run-scoring single among two hits and Brandon Belt hit a sacrifice fly for the Giants, who look to take a 2-0 lead in the best-of-seven series Sunday night in St. Louis. Sergio Romo recorded the final out of the eighth and Santiago Castilla pitched a perfect ninth for his third save of the postseason.

Bumgarner (2-1) allowed four hits and one walk, and stymied the Cardinals in a 112-pitch effort. St. Louis ace Adam Wainwright (0-1) gave up three runs (two earned) and six hits in 4 2/3 innings.

Sandoval doubled, Hunter Pence walked and Belt singled to load the bases in the second. One out later, Ishikawa placed a blooper into shallow left field for one run, and a second scored later in the inning when Cardinals third baseman Matt Carpenter misplayed Gregor Blanco’s grounder for an error.

Posey and Sandoval singled to start the third and Poesy eventually scored on Belt’s fly to center. St. Louis put two runners on against Bumgarner in the seventh before the left-hander retired Kolten Wong on a grounder and struck out Tony Cruz to end the threat.

GAME NOTEBOOK: Bumgarner set a postseason record for most consecutive scoreless innings (26 2/3) on the road, dating back to 2010. … CF Jon Jay had two of St. Louis’ four hits. … San Francisco has won seven straight and 16 of its last 20 postseason road games.