Marquis (5-1) drove in two runs in the first with an RBI double, and added a single in the fourth. He allowed two runs in the second — one of them unearned — and two in the seventh, but still got credit for snapping Florida's eight-game winning streak in Washington.
Vazquez (2-4), who left the team for three days after the death of his wife's relative in Puerto Rico, allowed six runs and six hits in four innings.
Todd Coffey relieved Marquis and Emilio Bonifacio greeted him by ricocheting a ball off his right forearm, and he had to leave. With runners on first and second, Tyler Clippard retired Hanley Ramirez to end the seventh and pitched a scoreless eighth. Cole Kimball worked the ninth.
Roger Bernadina led off the first with a bunt single, and Jayson Werth reached on an infield hit of his own. Laynce Nix singled to score Bernadina. and after Adam LaRoche walked to load the bases, Rodriguez singled to score Werth and Nix.
LaRoche scored on Jerry Hairston's fielder's choice. After Alex Cora singled, Marquis doubled to left to score Hairston and Cora — but Marquis was thrown out at third.
The Marlins scored two unearned runs against Marquis in the second.
Gaby Sanchez reached on an error by Hairston, and Logan Morrison doubled to extend his hitting streak to 13 games. Sanchez scored on a sacrifice fly by Mike Stanton and Morrison came home on Brett Hayes' single.
The Nationals scored their seventh run on an RBI double by Rodriguez in the fifth, and Florida scored its runs in the seventh on RBI singles by Greg Dobbs and Craig Coghlan.
Washington's final run scored on an RBI single by Bernadina in the eighth.
NOTES: Nationals prospect Bryce Harper had his 18-game hitting streak end when he went 0 for 4 with a walk for Hagerstown. The former No. 1 draft pick is hitting .381 in the Class A South Atlantic League. ... Hairston's error was the first by the Nationals in the last 10 games. They had tied a franchise-high with nine straight errorless games. ... Florida 2B Omar Infante didn't start for the first time this season. He pinch-hit in the ninth inning. ... Infante and Sanchez are the only Marlins to play in every game. ... C John Buck didn't start for just the fifth time this season. Hayes caught instead. ... Washington SS Ian Desmond (sore left quad) did not play for the second straight game. ... Nationals 3B Ryan Zimmerman played catch for the first time since his surgery for a torn abdominal muscle on May 3.