Vogelsong (2-0) tamed the Cardinals on one run, allowing four hits while walking one and striking out nine as the Giants staved off elimination for the second straight game and evened the National League title series at 3-3.
The series is to be decided Monday with the winner advancing to the World Series against the Detroit Tigers. The World Series is scheduled to begin Wednesday.
Vogelsong triggered a four-run second inning when St. Louis shortstop Pete Kozma mishandled his infield grounder, allowing Brandon Belt to score, and Marco Scutaro added a two-run double in the big frame.
Chris Carpenter (0-2) absorbed the loss, surrendering five runs (two earned) on six hits over four innings for the Cards.
Allen Craig got the only RBI for St. Louis.