
The Nats (71-70) mustered just three hits against returning Marlins ace Jose Fernandez (5-0, 2.06 ERA) and four Miami relievers.
Fernandez went five innings in his return, giving up two hits and walking one, striking out seven, throwing 69 pitches, 43 for strikes.
Tanner Roark (4-5, 4.38 ERA) took the loss, charged with two runs on eight hits in four and two-thirds innings, striking out two and walking one.
The Nats entered the week four games back of the New York Mets in the NL East, but were swept by the Mets in a weekday series at Nationals Park, and have now dropped the first two games of their series at Miami.
The Mets are on a six-game winning streak at the same time.