Stanton led off the sixth with his 11th home run. Ozuna singled and scored on Fernandez’s single later in the frame, two innings after both he and Stanton were briefly motionless on the Nationals Park warning track.
"It wasn’t like a head-on blaster, but you don’t really know what happens on that," said Marlins manager Don Mattingly, who was part of the contingent that attended to both players on the field. "Especially when they don’t get up. I think that bothers you more than anything."
With no one on against Fernandez, Zimmerman drove a full-count curveball into the gap in right center.
As Stanton and Ozuna chased it, their legs clattered together, sending both tumbling. Stanton crashed into the out-of-town scoreboard and Ozuna hit the ground as the ball fell and Zimmerman scored easily.
"I was looking around for the ball kind of and I didn’t really put it together," said Stanton, a three-time All-Star who is in the second of a 13-year, $325 million contract. "I thought he had it, threw it in already. I was a little jacked up for a second."
Fernandez (5-2) struck out 10 and only allowed three balls in play after that moment, fanning the side in the sixth and seventh to help the Marlins secure a four-game split.
The win runs his all-time record against Washington to 5-0 with a 1.09 ERA.
"The whole season as the game has been progressing, I’ve been feeling better and better every time,"said Fernandez, who pitched through the seventh for a second consecutive start. "I feel like I could’ve kept pitching."
J.T. Realmuto singled three times and scored twice for the Marlins, who took a 2-0 lead on an error by Nationals second baseman Stephen Drew. A.J. Ramos came on in the ninth for his 11th save.
Nationals starter Joe Ross (3-3) allowed five runs – three earned – over 5 2/3 innings.
Washington struck out 15 times, with big league batting leader Daniel Murphy a late scratch due to illness.
"I think the doubleheader yesterday kind of got us all a little bit, and the skipper kind of took it out of my hands and gave me the day," said Murphy, who pinch hit in the ninth. "And personally, I could use that."
HISTORY INSIDE THE PARK
Zimmerman’s homer was the first inside-the-park shot and the third since the Nationals started playing in Washington in 2005. It was the 26th in Montreal/Washington franchise history.
Before the game, the Marlins recalled LHP Jarlin Garcia from Triple-A New Orleans and optioned RHP Nick Wittengren there. Garcia did not appear Sunday. When he does, it will be his big league debut.
Marlins: RHP Kendrys Flores was also sent to Triple-A New Orleans after exiting his start Saturday after three innings with a shoulder strain. Flores had been added to the roster as the Marlins’ 26th man to pitch the second game of a split doubleheader.
Nationals: Murphy was originally slated to hit fourth in the series finale. He’s now batting .400 with five homers and 23 RBIs.
Marlins: LHP Adam Conley (2-2, 3.72) looks for his first career victory against the Phillies in the first of three at Citizens Bank Park on Monday. Conley has pitched well against Philadelphia, allowing two runs in 18 IP over three starts.
Nationals: Fresh off his historic 20-strikeout performance, RHP Max Scherzer (4-2, 4.15) will square off against Mets RHP Noah Syndergaard (3-2, 2.53) in the opener of a three-game set at Citi Field.