Washington earns series split with Arizona, wins 8-3
The win gave the Nats (56-51) a series split with the Diamondbacks and moved them to a game and a half back of the New York Mets in the National League East.
Washington is also three games out of the second wild-card spot in the NL.
Ross (3-3, 2.80 ERA) gave up a run on five hits in six innings of work, striking out seven without issuing a walk.
Ross, a rookie, has yet to give up more than three runs in any of his eight starts in 2015.
Washington never trailed, taking the lead in the second on a solo homer by Ian Desmond, his 12th of the season, then going up 2-0 in the fourth on an RBI groundout by Michael A. Taylor.
A Jarrod Saltalamacchia solo homer in the fifth cut the lead to 2-1. A Wilson Ramos two-run single in the bottom of the fifth pushed the Washington lead to 4-1.
A two-run double by Ender Inciarte in the seventh cut the margin to 4-3. Ryan Zimmerman answered for the Nationals in the bottom of the seventh with an RBI double that made it 5-3, and a three-run Clint Robinson homer in the eighth accounted for the final margin.
Bryce Harper was 2-for-2 at the plate and walked three times.