WASHINGTON — Bryce Harper looked simply bewildered during his first three at-bats against the Phillies, all ending in swinging strikeouts. He came through big in his fourth plate appearance.

Harper hit a three-run home run in the bottom of the eighth inning to lift the Washington Nationals to a 3-0 victory over the Philadelphia Phillies on Saturday night.

Harper whiffed repeatedly against Phillies starter Jerad Eickhoff. He then provided the game’s only scoring against Patrick Schuster, who threw a wild pitch, issued a walk and gave up the homer without recording an out after replacing fellow reliever Luis Garcia (1-1).

“I was thinking to myself, ‘well, you struck out three times. Hit a homer and everybody will forget about that,'” Harper said. “Look what happened.”

Nationals ace Max Scherzer gave up four hits in 6 2/3 scoreless innings, and struck out eight to increase his NL lead to 251.

Shawn Kelley (2-2) recorded the final out of the eighth and Mark Melancon pitched ninth for his 40th save as Washington won for the fifth time in six games.

Ben Revere’s single with one out in the eighth started the winning rally against Garcia, who was recalled from Triple-A Lehigh Valley before the game. Daniel Murphy walked before Harper’s heroics.

The 2015 NL Most Valuable Player starred at the drive down the right field line before punctuating the drama with a bat flip.

“That was a dramatic home run,” National manager Dusty Baker said. “It just shows how strong he is mentally after you strike out three times and hit a home run. He had a rough night going up to then.”

Facing a 3-1 count against Schuster, Harper had one objective in mind.

“I was kind of shocked he threw it over the middle of the plate,” Harper said of Schuster’s curveball. “I was swinging no matter what anyway, to tell you the truth. If it had been in their dugout I probably would have swung at it.”

Eickhoff essentially matched Scherzer, keeping Washington off the scoreboard over six innings. He gave up five hits and struck out five.

Tied for the NL lead with 16 wins, Scherzer won each of his previous four starts with 32 strikeouts and a 2.45 ERA in that stretch. He entered Saturday’s matchup 3-0 against Philadelphia this season.

The Cy Young contender wasn’t special throughout — he hit two batters — and labored at times with long innings. He also got clutch outs when needed.

With two runners on and one out in the first, Scherzer induced back-to-back infield pop-ups. He struck out Tommy Joseph to end the third with two runners in scoring position.

“I didn’t think (Scherzer) was at his best tonight,” Phillies manager Pete Mackanin said. “He had a ton of pitches. He looked like he was struggling with command and we just couldn’t take advantage of it.”

Philadelphia’s defense kept the game scoreless in the fourth. Jose Lobaton’s single with runners at first and second sent Clint Robinson around third. Center fielder Odubel Herrera’s throw bounced to home, where catcher Cameron Rupp shielded the plate and tagged out Robinson.

TRAINER’S ROOM

Phillies: 3B Maikel Franco pinch-hit in the seventh inning after sitting out the previous two games with a sore right thumb.

Nationals: RHP Joe Ross, on the disabled list since July 3 with right shoulder inflammation, threw 60 pitches during a simulation at Nationals Park Saturday. “(Joe) had good velocity. … Changeup looked like he’d never been out,” manager Dusty Baker said.

STRASBURG SPEAKS

Nationals pitcher Stephen Strasburg made his first comments since leaving Wednesday’s start with a strained flexor mass in his right elbow. Strasburg passed on projecting a timeline for his return before or during the postseason.

“I can’t make that claim,” he said. “There’s still pretty much a month left in the season. I’m just trying to get back healthy. Hopefully we’re still playing baseball.”

BLANK CHECK

Saturday marked the third time the Phillies were shut out by the Nationals this season and the 10th time they were held scoreless overall.

UP NEXT

Phillies LHP Adam Morgan (2-9, 5.90) faces LHP Gio Gonzalez (10-9, 4.40), who allowed six runs and eight hits in three innings in his last start on Monday against the Braves.