SAN FRANCISCO (AP) ― San Francisco’s Travis Ishikawa hit a three-run homer in the bottom of the ninth inning, sending the Giants to the World Series with a 6-3 win over the St. Louis Cardinals on Thursday.

The Giants clinched the NL Championship Series 4-1 and now will face the Kansas City Royals in a World Series between two teams that began the playoffs in sudden-death wild-card games.

San Francisco, which won the 2010 and 2012 World Series, will be on the road for this year’s opener on Tuesday.

Pablo Sandoval singled to start the ninth against pitcher Michael Wacha, who was making his first appearance of the postseason for the Cardinals. After one out, Brandon Belt walked to bring up Ishikawa, who drove a pitch beyond right field to trigger an orange towel-waving frenzied celebration.

It was the first time a homer sent the Giants into the World Series since perhaps the most famous drive ever in baseball ―Bobby Thomson’s “Shot Heard Round the World” in a 1951 playoff.

“These guys have been through it,” Giants manager Bruce Bochy said. “They have been battle-tested and they know how to handle themselves on this type of stage, and then add to that the kids that we brought up, and then Ishikawa. I mean, what a great story.”

Ishikawa knew right away on his first career postseason homer, raising his right arm into the air as he watched his ball sail into the seats.

He emphatically threw his helmet down to the dirt in triumph and joined his jubilant teammates at home plate as fireworks shot off from the center field scoreboard.

The Giants had tied the game in the bottom of the eighth when pinch-hitter Michael Morse homered leading off against Pat Neshek, who had just replaced Cardinals starter Adam Wainwright. Morse was batting for San Francisco starter Madison Bumgarner, who was named series MVP.

The Giants had three homers in all ― Joe Panik hit a two-run drive in the third ― after having gone six games without clearing the fences.

“Just a gutty effort through all this and I couldn’t be prouder of these guys. They just don‘t stop fighting,” Bochy said.

Ishikawa began the season as Pittsburgh’s first baseman, but was soon cut.

He resigned with the Giants, his original team, and went to the minor leagues before making it back to the majors.

Thursday’s game was a microcosm of his topsy-turvy as his season.

Earlier in the game, he misplayed a flyball to left field that cost his team a run. He more than made up for it with his final swing.

Bumgarner did not allow a hit after Matt Adams and Tony Cruz homered in the fourth to give the Cardinals a 3-2 lead.

He lasted eight innings, and closer Santiago Casilla worked out of a bases-loaded jam in the top of the ninth.

Adams drew a one-out walk and Daniel Descalso entered to pinch run.

Randal Grichuk singled and Descalso reached third on Kolten Wong’s grounder.

The second out came on a force out at second, but Cruz walked to load the bases again after consecutive pitches near his head. A pitching change brought in Jeremy Affeldt, who fielded an Oscar Taveras grounder and sprinted to first base to end the inning.

Cardinals manager Mike Matheny turned to Neshek after Wainwright reached 97 pitches and retired his final 10 batters in order.

For the bottom of the ninth, Matheny made a pitching change that will be second-guessed all offseason.

He went with Wacha, the hard-throwing star of last year’s NLCS. But Wacha had missed much of the summer with an injury and had not pitched in 20 days.