
Pittsburgh (47-45) seemed poised to win the game nine innings earlier, but a two-out, two-strike pinch-hit homer by Daniel Murphy (.350/.388/.608, 18 HR, 67 RBI) sent the game to extras.
Marte went deep off reliever Oliver Perez (2-3, 4.91 ERA, 1.32 WHIP), the eighth Nats pitcher.
Pittsburgh rookie Chad Kuhl outdueled Washington ace Max Scherzer in his fourth Major League start, allowed just one hit in six innings of work, striking out five.
Scherzer (10-6, 2.94 ERA, 0.96 WHIP) battled all day long, giving up a run on six hits in seven innings of work, striking out seven and walking one.
Washington (56-37) had eight hits in 57 at bats off nine Pittsburgh pitchers.