Giants 4, Nationals 3: Hector Sanchez delivered a pinch-hit three-run homer in the ninth as visiting San Francisco came from behind to stun Washington.

Rafael Soriano (2-3) was trying to lock down his third save of the series but surrendered a leadoff single to Buster Posey before retiring the next two batters. Roger Kieschnick drew a walk in front of Sanchez, who sent a 3-2 fastball out to right to put the Giants on top.

Javier Lopez (2-2) worked 1 2/3 perfect innings to earn the win in relief and Sergio Romo retired the side in the bottom of the ninth for his 29th save. Brandon Belt added a solo home run for San Francisco, which snapped a three-game slide.

Ian Desmond drove in a pair of runs and scored in a three-run third inning while Dan Haren allowed a run on three hits over six frames as the Nationals had a five-game winning streak come to an end.

Giants starter Ryan Vogelsong was reached for three runs on six hits in 3 2/3 innings but five relievers combined to allow two hits while striking out five the rest of the way. Belt broke up the shutout in the sixth with an opposite-field drive into the bullpen in left-center.

GAME NOTEBOOK: The Nationals are 9 1/2 games behind the Cincinnati Reds for the second National League wild-card spot and 14 1/2 games behind the Atlanta Braves in the NL East. … Giants RHP Sandy Rosario was hit with a comebacker in the chest by Adam LaRoche in the seventh inning and left the game. … Washington will try to cut into its huge deficit in the East when it starts a three-game series at Atlanta on Friday. San Francisco continues its road trip at Miami.