Brayan Villarreal walked Marco Scutaro with the bases loaded and two outs in the bottom of the ninth, handing the San Francisco Giants a 3-2 victory over the Boston Red Sox on Tuesday night.
Roger Kieschnick started the winning rally with a one-out single off Franklin Morales (2-1). The Giants loaded the bases with two outs when Morales walked Andres Torres and hit pinch-hitter Hector Sanchez with a pitch on the left wrist.
Villarreal, acquired last month from Detroit, then threw four straight balls to Scutaro in his first appearance with the Red Sox, giving the defending World Series champions a rare reason to celebrate this summer.
The Red Sox couldn't hold a 2-0 lead and lost for the fifth time in seven games to fall percentage points behind Tampa Bay for the lead in the AL East.
Sergio Romo (4-6) pitched a perfect ninth for the win.
After twice failing to get a runner in from third with no outs, the Giants finally delivered in the eighth inning to tie the game.