WASHINGTON — Howie Kendrick hit a game-ending grand slam in the 11th inning, and the Washington Nationals beat the San Francisco Giants 6-2 on Sunday in the finale of a day-night doubleheader.

Daniel Murphy and Ryan Zimmerman also homered for Washington in the makeup of Friday night’s rainout. Max Scherzer struck out 10 in seven innings and Matt Albers (6-2) pitched two scoreless innings for the win.

San Francisco took the opener 4-2, with Chris Stratton striking out a career-high 10 in 6 2/3 shutout innings.

It was Washington’s first day since slugger Bryce Harper got hurt Saturday when he slipped on first base. The All-Star has a significant bone bruise in his left knee but no ligament damage, general manager Mike Rizzo said. The Nationals hope he can return this season.

Asked for his initial reaction when he tumbled, Harper said, “I don’t like wet bases.” His recovery time is not clear.

“Ten days or two weeks is a lot better than thinking the whole season and the postseason,” Nationals manager Dusty Baker said.

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Harper is batting .326 with 29 homers and 87 RBIs this season.

“I thought to myself, ‘It’s 10 o’clock at night and we’re playing a game in the rain, so I was really upset about that, as well. It’s just a freak accident, freak situation. I think (the season) flashed before your eyes and you realize there’s nothing you can do,” Harper said. “I think we got the best possible news that we could.”

Murphy singled off Albert Suarez (0-2) leading off the 11th and raced to third on Zimmerman’s bloop hit. After Suarez intentionally walked Anthony Rendon, Kendrick homered to left.

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Scherzer, who tossed a five-hitter in a 3-1 victory at San Francisco on May 31, allowed two runs and five hits. The two-time Cy Young Award winner has dropped a decision since June 21, but he lost the lead on Pablo Sandoval’s solo homer in the seventh.

Washington’s defense saved Scherzer a run in the fourth. Hunter Pence’s single drove in Denard Span, but center fielder Michael A. Taylor threw out Joe Panik trying to score from second.

Matt Moore pitched seven innings of two-run ball for San Francisco and struck out a season-high nine.

Stratton (1-2) allowed five hits and one walk in his fourth major league start in the opener, and Sam Dyson got three outs for his ninth save in 14 chances.

Washington did not advance a runner to scoring position until the seventh.

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“I thought we attacked the zone pretty good today,” Stratton said. “I thought in the past I had nibbled around a little bit, so I didn’t want to do that.”

Panik had three hits, including a two-run single in San Francisco’s three-run second.

Pinch hitter Kelby Tomlinson added a sacrifice fly in the eighth for a 4-0 lead. He also struck out in each of his four at-bats in the second game.

Rendon hit a two-run homer in the eighth against Hunter Strickland. San Francisco’s A.J. Cole (1-3) allowed three runs and six hits in six innings.