Giants 9, Cardinals 0: Matt Cain worked 5 2/3 scoreless innings and San Francisco erupted for seven runs in the first three innings to earn its 19th World Series appearance with a convincing victory in Game 7 of the National League Championship Series.

Hunter Pence’s two-run double sparked a five-run third inning for the Giants, who improved to 6-0 when facing elimination this postseason. San Francisco begins the World Series at home against the Detroit Tigers on Wednesday.

Cain (2-2) allowed five hits and struck out four as the Giants became the seventh team to win an LCS after trailing 3-1 since the best-of-seven format was introduced in 1985. St. Louis scored only once in the last 23 innings and went 0-for-11 with runners in scoring position in Game 7.

After scoring one run in each of the first two innings, San Francisco sent 11 batters to the plate in the third and scored five runs on four hits and three walks. Cardinals starter Kyle Lohse (2-1) was pulled after allowing the first three batters of the inning to reach base.

Lohse walked Buster Posey to load the bases before Joe Kelly came on to face Pence, who hit a broken-bat grounder that eluded shortstop Pete Kozma and scored two runs. Another run scored when center fielder Jon Jay misplayed the ball for an error.

Giants second baseman Marco Scutaro had three hits and went 14-for-28 in winning the series MVP award, tying the major league record for most hits in an LCS. Brandon Belt added a solo blast in the eighth for his first career postseason home run.

Yadier Molina went 4-for-4 for the Cardinals, who were outscored 20-1 in the last three games. St. Louis lost for the first time in seven elimination games dating back to last year.

GAME NOTEBOOK: The Giants improved to 1-5 in best-of-seven deciding postseason games. …Cardinals LF Matt Holliday went 1-for-4 after missing Game 6 with a stiff back.. …San Francisco improved to 6-1 this postseason when scoring four or more runs in a game. … 3B Pablo Sandoval’s run-scoring groundout in the first gave him an RBI in five straight games to match a Giants postseason record. … The team that scored first went 6-1 in the series. ...The final half-inning was played under a steady rain.