From his customary second spot in the batting order, the Giants second baseman went three for four on the night with a double and a sacrifice bunt and was in the middle of the team's infield celebration after closer Brian Wilson struck out Phillies slugger Ryan Howard looking on a 3-2 pitch to end the game.
Sanchez struck out in his first at bat in the top of the first inning, but helped set up the Giants' two-run, third-inning rally that tied the game at 2.
With runners at first and second base and no outs, Sanchez laid down a bunt to advance both runners, one of which would score on Aubrey Huff's single one batter later. A fielding error would allow the tying run to score.
The game would remain deadlocked until Juan Uribe's game-winning solo home run in the top of the eighth inning, as Sanchez singled with one out and a man aboard in the top of the fifth, but was stranded in that inning and again in the seventh after doubling into the left-field corner with two outs for his first extra-base hit of the series. The Giants left 11 runners on base Saturday.
In the top of the ninth, the Giants appeared ready to add to their lead when Sanchez extended a one-out rally with a single. San Francisco would leave the bases loaded.
Sanchez, who spent most of his career with the Pittsburgh Pirates before being traded to San Francisco midseason in 2009, had a good series at the plate, batting .360 (nine for 25) with one run batted in and one run scored.
He's batting .268 overall in the postseason, which began with a 3-1 series win over the Atlanta Braves in the division series.
The Giants have won the World Series five times, but have not done so since moving from New York to San Francisco in 1958, despite three opportunities, with the most recent coming in 2002. Their last World Series win came in 1954.
"We have a bunch of guys on this team that just want to win, and we'll do whatever it takes to get there," Sanchez said. "It was amazing. This is the best group of guys that I've ever played with."