MIAMI -- Miami Marlins right fielder Giancarlo Stanton knows the significance of this three-game series against the Washington Nationals, and he played like it on Tuesday.

Stanton drove in two runs, and right-hander Henderson Alvarez outdueled Stephen Strasburg as the streaking Marlins beat the Nationals 3-0 at Marlins Park.

"The easiest way to gain ground is head to head," said Stanton, whose Marlins pulled to within five games of the Nationals, who started the night atop the National League East. "If we sweep them, that's three games. If we get two out of three, that's only one game."

The Marlins (53-53), who have won a season-best six games in a row and nine of their past 10, will go for that sweep on Wednesday. But, for now at least, they are at .500 for the first time since June 25.

Stanton, who had been hitless in his past 11 at-bats, including eight strikeouts, broke out of his slump by pulling a high breaking pitch down the left-field line for a run-scoring double. That snapped a scoreless tie in the sixth.

"I figured (Strasburg) was going to pound me in like they have been doing the past two days," Stanton said. "They were throwing me off-speed pitches, too; I haven't looked too great against those. I just wanted to see something up and over the plate, and that's what I got."

Left fielder Christian Yelich added a run-scoring double in the eighth inning. Pinch-hitter Reed Johnson, who had singled to start the inning, scored on the play. Stanton then followed with a line single over a drawn-in infield, smacking an 0-2 pitch.

Alvarez (8-5) pitched seven innings, allowing three hits, four walks and no runs. It was Alvarez's first career win against the Nationals -- he had entered the game 0-3 in six previous starts.

Marlins relievers Bryan Morris and Mike Dunn worked the eighth, and closer Steve Cishek pitched the ninth for his 27th save. He stranded the bases loaded when he struck out third baseman Anthony Rendon.

Strasburg (7-9) pitched seven innings, allowing four hits, two walks and one run. Strasburg has more wins against the Marlins -- seven -- than any other team. But he could not add to his total on this night.

Washington (57-47) lost its first series since July 10, when it dropped two of three against the Baltimore Orioles.

The only bad news for the Marlins was that first baseman Jeff Baker, the hero of Monday's dramatic come-from-behind win, had his career-long 11-game hitting streak snapped. He went 0-for-3.

Second baseman Jordany Valdespin started Miami's initial rally with a single to lead off the sixth. He then sped home on Stanton's double.

"(Strasburg) threw the ball really well tonight with the exception of that hanging breaking ball to (Stanton)," Nationals manager Matt Williams said.

Alvarez worked out of a bases-loaded, no-out jam in the second inning. After allowing a walk, a single by left fielder Bryce Harper and another walk, Alvarez struck out second baseman Danny Espinosa.

Right fielder Nate McLouth followed with a hard line drive, but Marlins third baseman Casey McGehee saved a couple of runs by making a diving catch. Alvarez got the final out of the inning by getting Strasburg to ground out to second.

"I didn't feel very good," Alvarez said of his pre-game preparation. "I wasn't into it. For several innings, I had to fight through it. When the bases were loaded (in the second), I started to find my control."

Washington also wasted a leadoff double by Rendon in the sixth. Rendon was stranded at third when shortstop Ian Desmond grounded out to end the inning.

Williams said his Nationals, who have been battling the Atlanta Braves for first place in the division most of this season, are also wary of the Marlins.

"They have the ability to roll off wins -- it starts with their pitching," Williams said. "It's up to us to win that one (on Wednesday)."

NOTES: The Marlins sent OF Jake Marisnick to Triple-A New Orleans after the game. ... Nationals RF Jayson Werth did not start because of a swollen right ankle, although he flied out as a pinch-hitter. Manager Matt Williams said he hoped Werth could start Wednesday. OF Nate McLouth, who entered Tuesday batting just .180, played in place of Werth. ... Williams said 3B Ryan Zimmerman (hamstring) is at least two weeks away from returning. ... Monday's 7-6 win was the first time in 11 years that the Marlins came back from six runs down in the seventh inning or later. ... The Marlins will start LHP Brad Hand in Wednesday's series finale against Washington RHP Tanner Roark. Miami won three of Hand's past four starts, and he lowered his ERA from 6.21 on July 3 to 4.19. ... Roark is 12-7 with a 2.67 ERA in 24 career starts.