Nats starter Joe Ross left after two innings with a blister, but the bullpen picked up the slack in a 3-1 Washington win in Miami on Wednesday.
Yusmeiro Petit (1-0, 3.24 ERA) picked up the win in relief, allowing two hits and one run in four innings, striking out three.
Jonathan Papelbon recorded his sixth save of the season, allowing a hit in a scoreless ninth.
Michael A. Taylor hit a solo homer in the fifth. Bryce Harper was 1-for-4 with an RBI double for Washington (11-3).