WASHINGTON (AP) -- Standing at the plate with a chance to make baseball history, Bryce Harper insisted his focus was on driving in the runner from third base.
He did, however, acknowledge the thought of hitting a fourth home run wasn't entirely banished to the back of his mind.
Harper homered three times in a game for the first time and had five RBIs in his finest day with the Nationals, leading Washington over the Miami Marlins 7-5 Wednesday for its third straight series win.
Harper hit a 393-foot solo shot in the second inning, a 442-foot, two-run drive in the third and a 445-foot bases-empty homer in the fifth, the last two reaching the second deck. Each came on the second pitch of the at-bat off Tom Koehler (2-3), and they raised Harper's season total to eight.
With an opportunity to tie major league record of four homers in a game, Harper hit a run-scoring groundout to second base against Sam Dyson in the seventh.
''Going up there against Dyson, runner on third base, you're trying to get that run in,'' Harper said. ''Of course you want to try to get that fourth homer. That's something that would've been very cool to get.''
It didn't happen, but Harper could console himself with reaching career highs in homers and RBIs. Now in his fourth major league season, he previously hit two homers in a game on five occasions.
He would like to think this kind performance, rather than the 1-for-17 slide that preceded it, would typify his style of play.
''That's how I should be. Plain and simple,'' Harper said. ''That's how I expect myself to play. Of course you're not going to do that every single day. You're not going to go out there and hit three homers, drive in five. But that's the type of player I need to be.''
He became the fourth Nationals player to hit three homers in game following Alfonso Soriano (2006), Adam Dunn (2010), and Ryan Zimmerman (2013).
Harper was 2 for 15 against Koehler before connecting three times over a six-pitch span.
''I made three mistakes against him and he hit the ball hard three times,'' Koehler lamented. ''Fastball away that stayed up, fastball in that was up and came back over the plate and a slider that just kind of spun up there.''
Max Scherzer (2-3) struck out 10 and allowed five runs and 10 hits over seven-plus innings. He entered with a 1.26 ERA but Washington scored a total of two runs in his three defeats.
Scherzer was pulled after giving up a three-run homer to Giancarlo Stanton in the eighth, but Harper did enough beforehand to make Miami's late surge meaningless.
''We're seeing him grow right in front of our eyes,'' Scherzer said of his teammate. ''That's special.''
Drew Storen got three outs for his eighth save, sealing the Nationals' second win in the three-game series.
With Harper leading the way, Washington hit two homers, three doubles and a single over the first three innings while building a 4-2 lead.
The barrage began in the second, when Harper hit an opposite-field drive to left on a 1-0 pitch.
In the third, two doubles and a sacrifice fly by Yunel Escobar made it 2-all before another Harper home run put the Nationals ahead for good.
Harper connected in the fifth inning with such force that Stanton stood motionless in right field, looking toward the infield as the ball soared into the seats behind him.
Marlins: Dee Gordon extended his hitting streak to 11 games with a fifth-inning single. ... Stanton's home run was his seventh. The rest of the team has nine. ... Justin Bour started in all three games of the series in place of slumping Michael Morse.
Nationals: Harper (22 years, 202 days) is the 10th-youngest player to hit 3 HRs in a game. ... It was Scherzer's 27th career game with at least 10 strikeouts.
Marlins: Miami hopes to activate OF Christian Yelich (lower back strain) off the DL during the four-game series in San Francisco that starts Thursday night.
Nationals: There was no update on RHP Stephen Strasburg, who left Tuesday's game after three innings with irritation beneath his shoulder blade. ... OF Jayson Werth missed a second straight day with a sore shoulder, the lingering effect of offseason surgery. ... RHP Casey Janssen (shoulder tendinitis) will begin a rehabilitation assignment Thursday with Class A Potomac.
Marlins: Miami opens a seven-game West Coast swing by sending Dan Haren (3-1, 2.70 ERA) to the mound Thursday night against the Giants.
Nationals: Washington enjoys what Williams called ''a welcome day off'' on Thursday before opening a three-game home series against the Braves.