SAN FRANCISCO, July 15 (UPI) --
Hector Sanchez singled home the game-winning run in the 12th inning Saturday and San Francisco grabbed the divisional lead with a 3-2 win over Houston.
The Giants initially seemed to be well on the way to a win with a two-run lead in the ninth and closer Santiago Casilla on the mound.
But with the Astros down to their final out, Justin Maxwell stroked an RBI double to score Scott Moore, cutting the Giants' lead to 2-1.
Houston then tied it on a bizarre play when Chris Snyder appeared to end the game on a strikeout, but the ball got away from the catcher, Sanchez. No one covered first base to receive the put-out, and Moore came around to score the tying run.
It stayed knotted until the 12th when Pablo Sandoval, Angel Pagan and Sanchez delivered three straight singles off Brett Myers (0-4) to score the winning run.
The victory, combined with the Los Angeles Dodgers' loss to San Diego, vaulted the Giants into first place in the National League West and allowed them to clinch their three-game set against the Astros.
Jeremy Affeldt (1-1) earned the victory after Giants starter Tim Lincecum tossed eight shutout innings, striking out 11.