WASHINGTON (AP) – Clint Robinson, a 30-year-old non-roster invitee by Washington in spring training who had just 13 major league at-bats before this season, hit a two-run homer in the seventh inning to give the Nationals a 2-1 victory over the San Francisco Giants on Friday night.

Robinson, playing first base in place of the injured Ryan Zimmerman, is 20 for 69 (.290) with four homers and 12 RBIs in his last 21 games. His homer off right-hander Jake Peavy (0-3) made a winner of left-hander Gio Gonzalez (6-4) who allowed a run and five hits in seven innings.

Buster Posey had homered on Gonzalez’s first pitch of the seventh inning to give San Francisco a 1-0 lead in the teams’ first meeting since the Giants beat the Nationals in five games in the 2014 NLDS.

Peavy came off the disabled list and looked sharp. He went 6.1 innings, giving up just three hits and two earned runs while striking out four. His only blemish was the two-run shot by Robinson.

The Giants will try to snap their four-game losing streak tomorrow against Washington. Game time is at 8:05 a.m. Pacific Time.