WASHINGTON - Rookie Zack Godley pitched six scoreless innings to continue a stellar start to his career, and the Arizona Diamondbacks homered four times in a 6-4 victory over the Washington Nationals on Monday night.

Nick Ahmed homered and had four hits as the Diamondbacks improved to 5-2 on their 10-game, bi-coastal road trip while handing the Nationals their fourth straight loss and knocking them out of first place in the NL East. The New York Mets, who beat Miami 12-1, took over first and lead the Nationals by one game.

Godley (3-0) won two of those games, and with Monday's victory he becomes the second Arizona pitcher to win in each of his first three major league outings.

David Peralta and Welington Castillo added back-to-back homers off Nationals starter Doug Fister (4-7) and Jake Lamb hit a high-arcing shot in the ninth in Jonathan Papelbon's home debut in Washington.

Fister allowed five runs over six innings.

Ryan Zimmerman homered for Washington, which scored all four of its runs in the ninth inning, forcing Brad Ziegler to come on for his 19th save.

Godley remains unblemished after being called up in July with no Triple-A experience and only three career starts with Double-A Mobile.

He has pitched six innings in all three of those outings, allowing 14 hits while posting a 1.50 ERA.

Godley retired his first nine batters on just 29 pitches Monday, striking out the side in the second.

In the fourth, he allowed two hits and a walk to load the bases, but induced Ian Desmond into an inning-ending grounder to short.

Fister matched Godley with two efficient innings. But in the third, Ahmed hammered Fister's 3-1 fastball into the visitors' bullpen, making it 1-0.

Peralta and Castillo connected in the fourth to make it 4-0, with Castillo's blast to left-centre bringing a smattering of boos from the home crowd.

A.J. Pollock's sacrifice fly made it 5-0 in the fifth.

TRAINER'S ROOM

Diamondbacks: Manager Chip Hale said Arizona may decide to activate RHP Chase Anderson (triceps inflammation) after just one rehab start and go with a six-man starting rotation. "We've been going around and round about what's best," Hale said. Anderson threw four scoreless innings in a Rookie Arizona League game Sunday.

Nationals: RHP Stephen Strasburg (left oblique strain) struck out 11 batters and allowed two runs in 5 2-3 innings for Triple-A Syracuse on Monday night, his second rehab start . CF Denard Span (back tightness) took ground balls in the outfield before Monday's game and will take live batting practice later this week, manager Matt Williams said.

UP NEXT

Arizona LHP Patrick Corbin (2-3, 3.21) looks for his first consecutive wins of the season against Nationals RHP Max Scherzer (11-8, 2.22), who is 2-0 with 1.29 ERA against his former team.