The game turned in a single inning. Washington scored three times in the fifth to break open a scoreless contest and defeat San Francisco 3-0 at Nationals Park.
Andrew Alvarez earned his first major league victory, allowing three hits over 4.1 innings with five strikeouts and no walks. The left-hander carried a 0.00 ERA into the game and maintained it with a dominant performance that kept the Giants off the scoreboard.
The decisive rally began when Nuñez scored on Ruiz's double to left field. Mead followed with a two-run homer to left, a 390-foot blast that brought Ruiz home and gave Washington a 3-0 lead it would not relinquish.
Robbie Ray took the loss despite a solid effort, allowing seven hits over six innings with seven strikeouts. The Giants managed eight hits but could not push a run across against Washington's pitching combination of Alvarez and Miles Mikolas, who combined to scatter seven hits.
Washington snapped a two-game losing streak to improve to 9-12. San Francisco's three-game winning streak ended as they fell to 9-12.