The Fish had just five hits and could only get a man to second base three times in the 5-0 defeat.
Washington began the scoring in the third when starter Brad Hand lost control of the strike zone and walked a pair of runners, including the first run of the game.
In the fourth, the Nats added two more on a pair of RBI hits by Anthony Rendon and Jayson Werth. Hand exited the game after just 3.1 innings of work.
Miami reliever Jose Urena came in and did a quality job of keeping the game within reach. He allowed one run on a swing by Matt den Dekker in his 2.2 frames of relief.
Den Dekker was only in the game as a replacement for the injured Bryce Harper. Harper was hurt on a first-inning collision with second baseman Derek Dietrich while rounding the bag on a routine ground ball. Dietrich found himself in a strange position while covering the bag and Harper didn't see him while making an aggressive turn. While Harper wanted to remain in the game, the Washington medical staff chose to take him out with the best intentions for their star in mind.
Meanwhile, Sherzer cruised from the start as he had little trouble during his eight innings of work. He struck out a total of six batters and eventually earned his 12th win of the year.
Already up 4-0, the Nats got their fifth and final run in the ninth when Wilson Ramos provided an RBI on a ground ball to third.
In the ninth, Felipe Rivero closed out the Marlins to secure the easy win for the Nationals.
For the Fish, Jeff Mathis was the lone player with more than one hit, going 2-for-3 with a single and a double.
Hand was hit with his sixth loss of the season as he gave up three runs, four walks and five hits in his short outing.