WASHINGTON – Washington Nationals first baseman Clint Robinson was slow getting out for his curtain call during Friday night's game against the San Francisco Giants.

He was right on time against Jake Peavy's fastball.

Robinson hit a two-run homer and Gio Gonzalez pitched seven strong innings as the Nationals defeated the Giants 2-1, spoiling Peavy's return from the disabled list.

After right fielder Bryce Harper walked on a 3-2 pitch leading off the seventh inning against Peavy (0-3), Robinson connected for his fourth home run of the season.

Shortstop Ian Desmond was already into his at-bat before Robinson came out to acknowledge the sellout crowd at Nationals Park.

"About as big a shot of adrenaline as you could possibly ask for," Robinson said of the curtain call.

"I was a little bit late with it. I think they had already gotten two pitches into the next batter before I got out there. I was trying to calm myself down because I was all messed up inside."

The 30-year-old Robinson, a non-roster invitee by Washington in spring training, had just 13 major league at-bats before this season.

Playing in the outfield and filling in for injured Ryan Zimmerman at first base, he has 20 hits in his last 69 at-bats (.290), with four homers and 12 RBIs.

"It's just about being at the right place at the right time," he said. "That's why you hear about guys who play for years and years and everybody always asks 'why.' It's because that opportunity's going to come eventually. Mine came this year and I'm trying to make the best of it."

Gonzalez (6-4), whose last start was rained out after one inning, allowed one run and five hits and struck out six. It was his first outing of the season without a walk.

"Gio was in command of all his pitches," Nationals manager Matt Williams said. "He was able to throw his changeups and curveballs for strikes, and locate well with the fastball, too."

Drew Storen pitched the ninth to post his 24th save as Washington snapped a three-game losing streak.

Nationals pitchers have allowed just 25 runs in their last 13 games.

"Starting pitching continues to carry us," Robinson said.

San Francisco first baseman Buster Posey sent Gonzalez's first pitch of the seventh inning over the center field fence for his 14th homer of the season.

The Giants have lost four straight.

"We couldn't do much offensively. That's a tough one," Giants manager Bruce Bochy said. "You need a good pitching effort to break this little streak we're in. We got it, but the offense wasn't there."

Peavy, who was activated Friday, was making his first start since April 17 after spending more than two months on the disabled list with a back strain.

In his return to Nationals Park, where he was the winning pitcher in Game 1 of the 2014 National League Division Series, the right-hander allowed two runs and three hits in 6 1/3 innings. He had four strikeouts and four walks.

"A lot to build on," Peavy said. "It's nice to show everybody here in this room (that I'm healthy). It's hard to simulate these big league games in the minor leagues. It's nice to get back in the swing of things."

Peavy compiled a 5.55 ERA in seven rehab starts but was solid in his first game back. After giving up two hits and a walk in the first inning, he retired 16 of 17 before walking Harper in the seventh.

Peavy lowered his ERA from 9.39 to 6.43 in his third start of the season.

NOTES: The Giants placed RHP Tim Hudson on the 15-day disabled list retroactive to June 27 with a right shoulder strain. The team also designated IF Travis Ishikawa for assignment and called up OF Ryan Hollis from Triple-A Sacramento. ... Washington C Wilson Ramos got the night off as Jose Lobaton started behind the plate. ... The Nationals unveiled their newest "Racing President" with Calvin Coolidge joining George Washington, Thomas Jefferson, Abraham Lincoln, Theodore Roosevelt and William Howard Taft in the fourth-inning mascot race.