Lance Lynn fielded the easy comebacker in the fourth inning and quickly turned to try to start a double play at second base.
Instead, his throw caromed off the bag and set the Giants on a path that would send the National League championship series back to San Francisco.
Lynn was dominant through three innings of Game 5 Friday night, but his throwing error was crucial in a four-run fourth as the Giants beat St. Louis 5-0 and pulled to 3-2 in the best-of-seven series.
The NLCS now moves back to San Francisco for Game 6 on Sunday. Game 2 starters, St. Louis' Chris Carpenter and the Giants' Ryan Vogelsong are scheduled to pitch.
Defending champion St. Louis is seeking to go to consecutive World Series for the first time since 1967 and 1968.
The Giants, World Series winners in 2010, have never won a postseason series after falling behind 3-1. But they did win three games in a row - all on the road - to overcome a 2-0 deficit and beat Cincinnati in the NL divisional series. ...