Harper’s 2nd HR a 424-foot walk-off

WASHINGTON — Bryce Harper wasn’t expecting a fastball with a full count from Joaquin Benoit. No matter. Harper hit a game-ending three-run drive with two out in the ninth Sunday to give the Nationals a 6-4 victory over the Phillies.

“Benoit’s tough with that devastating changeup he throws,” said Harper, who also hit a two-run homer in the third. “I thought he was going to throw it there 3-2, but he left one up.”

Harper had worked the count full against Benoit before driving a 97-mph fastball to center for a 424-foot home run, his fourth this season.

It was Harper’s fourth gameending homer and his first since May 9, 2015. Harper has hit 18 of his 125 big-league home runs against the Phillies.

“I made a mistake, and he made me pay,” Benoit said. “No excuses.”

Harper’s first home run, a two-run shot off Jerad Eickhoff, broke a 1-1 tie. But the Nationals trailed 4-3 in the ninth when Benoit walked Chris Heisey with one out. Adam Eaton singled before Anthony Rendon flied out.

“The thing that really got Harper up was the walk to Heisey,” Phillies manager Pete Mackanin said. “Walks seem to score when we issue them.”

The Nationals, who have come from behind in six of their seven victories this season, won two of three in the weekend series. They have won 15 of their last 19 games against the Phillies.

Nats starter Gio Gonzalez allowed three runs, two earned, on five hits and three walks in 71⁄3 innings. The effort was his longest outing in two years.

Cesar Hernandez went 3for-4, homered and scored twice for the Phillies.