Justin Bour did what he could to get the ball rolling in the opening frame. The big first baseman launched a three-run home run with one out against Nationals starter Stephen Strasburg to give the Marlins the early lead.
Trailing 3-0 in the third, it was Washington's turn to find their long-ball stroke. Jayson Werth laced a 3-2 fastball over the left-field fence to bring the Nationals within one.
The Fish got one run right back just an inning later when Derek Dietrich contributed a deep fly of his own off of the 27-year-old Strasburg.
Now down by two, the Nationals offense wasn't done quite yet. They once again found their stroke with three runs in the fifth and another two in the sixth.
Werth was the man who got things started in the fifth once again as he lined an RBI double down the third-base line to pull the Nationals back within one. Bryce Harper and Ian Desmond did their part to keep the line moving as they each contributed run-scoring singles to give Washington its first lead of the game.
In the sixth, with one runner on, it was the big man Clint Robinson's turn to flex his muscles with a pinch-hit, upper-deck home run to right field to push the Nationals' cushion to three.
With the lead in hand, the Nationals ended up using four relievers after the early departure of Strasburg to lock down their 66th win of the year.
The Fish did what they could to get the tying run to the plate in the ninth, but closer Jonathan Papelbon shut the door for his 22nd save of the year.
Marlins starter Brad Hand struggled for really the first time in the month of August as he lasted only 4.2 innings and coughed up five earned runs.
The Nationals used a collective effort to capture the win as every position player in the starting lineup got at least one hit in the afternoon.
Werth finished the game going 2-for-4 with three RBIs, two runs scored and a walk.
For the Fish, Bour had his three RBIs and Adeiny Hechavarria added three hits (but never scored) in the losing effort.