SAN FRANCISCO — San Francisco’s players, soaked to the core in a driving rain, began running around the field slapping high-fives with fans. Sergio Romo danced through the raindrops and Angel Pagan waved a black Giants flag as he ran, then stayed outside with his daughter well after everyone else had taken the celebration indoors to the clubhouse.

The World Series is back in the Bay Area — two years after the Giants won their first championship in San Francisco.

“We showed up here to win,” Pagan said. “And we’re going to carry that over into the World Series.”

The Giants got there with another improbable comeback, stunning the defending champion St. Louis Cardinals with a 9-0 victory in Game 7 of the NL championship series after falling behind 3-1 at Busch Stadium.

Hunter Pence got the Giants going with a weird double, Matt Cain pitched his second clincher of October and San Francisco rode Marco Scutaro’s steady bat yet again.

“The rain never felt so good,” Scutaro said. “We’re going to the World Series, this is unbelievable.”

San Francisco won its record-tying sixth elimination game of the postseason, completing a lopsided rally from a 3-1 deficit.

The Giants, who won it all in 2010, will host reigning AL MVP and Cy Young winner Justin Verlander, Triple Crown slugger Miguel Cabrera and the Detroit Tigers in Game 1 on Wednesday night.

Verlander is set to pitch Wednesday’s opener at AT&T Park. Giants manager Bruce Bochy insisted before Monday’s game he had not planned any further in advance.

Scutaro, the NLCS MVP, produced his sixth multihit game of the series and matched an LCS record with 14 hits, and Pablo Sandoval drove in a run for his fifth straight game.

The Giants outscored the wild-card Cardinals 20-1 over the final three games behind stellar starting pitching from Barry Zito, Ryan Vogelsong and Cain.

“It’s unbelievable, what else can you say?” Vogelsong said. “Just when you say we’re down, we stand up again.”

Romo embraced catcher Buster Posey as fireworks went off over McCovey Cove beyond right field.