Miami pulled even in the sixth inning on Giancarlo Stanton's first home run of the spring. The blast, an opposite-field shot off Casey Janssen, came on the slugger's 24th plate appearance. Stanton ended the day going 3-for-3 with two RBIs.
Washington had taken the lead in the fifth inning on catcher Clint Robinson's solo home run coming on Sam Dyson's first pitch of the inning.
Both starters worked four innings, and each allowed two runs.
Washington's Doug Fister scattered six hits and struck out one, and he was assisted by two double plays. Miami's Mat Latos struck out three, gave up two hits and two runs before his second spring start ended after 47 pitches.
The Marlins went with their projected everyday lineup.
"It was good," manager Mike Redmond said. "These guys are going to get to play here together down the road. It was good to see them feed off each other."
In the second inning, the Marlins took the lead on Adeiny Hechavarria's RBI single to left. Miami slapped three singles in the inning off Fister. Martin Prado reached on an infield single, and he went to third on Jarrod Saltalamacchia's single to right.
The speed of Dee Gordon set the table for Stanton's RBI single in the third inning. Gordon lined a double to right-center before tagging up and moving to third on Christian Yelich's fly ball to left. With one out, Stanton lined a single to center, his second hit of the day.
Washington rallied for two runs in the fourth inning, taking advantage of a pair of stolen bases.
Latos retired the first nine he faced, but in the fourth, Michael Taylor singled to right and stole second. Dan Uggla had an RBI ground-rule double to right. Uggla swiped third and scored on Ryan Zimmerman's RBI groundout to short.
Up next: The Nationals return to Space Coast Stadium in Jupiter, Fla., on Thursday afternoon to play the Tigers for the second time in three days at 1:05 p.m. ET on Gameday Audio. On Tuesday, home runs by Tony Gwynn Jr. and Kila Ka'aihue helped the Nationals defeat the Tigers, 6-4. Left-hander Gio Gonzalez will get the start for Washington on Wednesday. He was hit hard in his last start, allowing four runs in 2 2/3 innings against the Marlins.