Expected to help the Giants contend for the playoffs in the latter part of 2009, Sanchez spent much of his time with them injured. He missed the start of the 2010 season with a shoulder injury but became a key part of their infield as their starting second baseman after making his season debut on May 19. He batted .292 as San Francisco won the NL West. In Game 3 of the 2010 National League Division Series against Atlanta, he hit a two-out single against Craig Kimbrel in the ninth inning of a game the Giants trailed 2–1; they rallied to win 3–2 that inning. Sanchez batted .320 in the 2010 National League Championship Series against the Philadelphia Phillies, then became the first player to have doubles in his first three World Series at bats in Game 1 of the 2010 World Series, helping the Giants win their first World Series since 1954 as they defeated the Texas Rangers. Sanchez batted .289 through 60 games in 2011 but suffered another shoulder injury on June 10. He spent the next season and a half on the disabled list, then announced his retirement on December 21, 2015.