The 1997 team won 19 in August.
"I think the way we started, a lot of people don't believe in what we can do," manager Ozzie Guillen said, noting the team's 8-14 April. "The talent is there. This team, little by little, is starting to put stuff together. Little by little, they believe they can compete in this game."
Struggling closer Heath Bell worked a perfect ninth inning, striking out two, to preserve the win. Bell bounced back with his eighth save in 12 chances.
Bell was greeted with cheers as he raced to the mound, and he locked down the ninth, improving the Marlins to 5-3 in their 10-game homestand.
"The fans here were outstanding today, giving the kid a little confidence," Guillen said. "I know it's a tough thing to do, but this is my job. The last thing you want to do is just don't believe in your players. When you don't believe in your players, you're done."
To get on track, Bell's going back to basics.
"I'm just going to go out there and pitch my game," the right-hander said. "I don't care if I [stink], I [stink], but I'm going to pitch my game. All I told myself is I was going to go out there and pitch my game. I'm not going to pitch anybody's game, but mine."
Overall, it was a solid team win for Miami, which is starting to put things together.
Washington's Jordan Zimmermann was charged with four runs in six innings, and the pitcher hit his first big league homer.
After falling behind 3-1, Hanley Ramirez singled off Zimmermann and Stanton crushed another of his trademark blasts. The two-run shot bounced off the Clevelander sign beyond the wall in left field.
"It's always good to do that and tie it up in that situation," Stanton said. "We kept it rolling and got two more."
It was Stanton's 12th homer of the season and 11th in May, which is one shy of Dan Uggla's team record in any month. Uggla had 12 in May 2008.
"Just better pitch selection," Stanton said of his power surge. "The at-bat before, I was just swinging at stuff in my face or in the dirt. In my next at-bat, I took those pitches."
The Marlins added the go-ahead run in the inning on Chris Coghlan's sacrifice fly to left, which scored Morrison, who doubled.
"Zimmermann pitched a good ballgame, he just made a bad pitch to Stanton," Washington manager Davey Johnson said. "He threw a hanging slider over the middle of the plate. That's not a good idea against one of their hotter hitters."
Zambrano came out for the seventh and ran into trouble after walking pinch-hitter Roger Bernadina and allowing a single to Steve Lombardozzi. Zambrano was lifted after 111 pitches, and lefty Dan Jennings retired Bryce Harper on a fly ball to left field. Coghlan made a sliding catch for the out.
"I just ran to a spot I thought it was going to be," Coghlan said. "In the last couple of steps, you make up your mind, 'Do I have to lay out for it or slide?' Fortunately, I made the play."
Edward Mujica took over to face Ryan Zimmerman, who grounded into a 6-4-3 double play.
"Mujica came in and he threw a good pitch and he got a double play," said Zambrano, who improved to 3-3. "That's what everybody was expecting in that situation.
"I tell you what, I found out why those guys are in first place. Those kids can hit. They have good pitching. They're good. The only mistake I made today was to the pitcher, Zimmermann."
The hustle of Reyes helped pad the lead in the seventh. Reyes blooped a double into short center field off Henry Rodriguez. He advanced to third on Omar Infante's groundout to third, and he scored on Ramirez's sacrifice fly to short center.
"Jose Reyes made a difference today, one run difference," Guillen said. "That's what I love about baseball. All you guys maybe want to see Stanton hit the ball 700 feet, but that's my game right there. Double, make it to third base, that's the baseball I love. That run was huge."
Zimmerman has hurt the Marlins throughout his career. And the veteran third baseman did so again in the fifth inning, delivering a two-run double to left-center, giving Washington a 3-1 lead. Zimmerman has played 100 games against the Marlins, and he has 54 RBIs.
The Nationals grabbed the lead in the first on Zimmermann's first career home run, a shot to left field.
In the fourth inning, Morrison's home run to right made it 1-1.
On Memorial Day, Morrison continued his tradition of saluting to the heavens when he crosses home plate in honor of his father, Tom Morrison, who was formerly in the Coast Guard. Tom passed away in December 2010.
"I had goosebumps going around the bases," Morrison said. "Giving him a salute was pretty cool."