Joe Ross took the loss in his return to the Washington Nationals rotation in a rain-shortened 6-2 decision at Atlanta on Sunday.
Ross (7-5, 3.48 ERA, 1.28 WHIP), in his first start since July 2, was on a 50-pitch count, and gave up a run on six hits in three innings, striking out five without issuing a walk.
The game was shortened to seven innings after two delays totaling two hours, 57 minutes.
The Nats (88-61) saw their lead in the NL East reduced to eight games over the New York Mets (80-69) with their second straight loss.
Jayson Werth and Bryce Harper had back-to-back run-scoring hits in a two-run sixth for Washington.