Drew Pomeranz picked up a signature win by outdueling Stephen Strasburg, and Tyler Colvin went deep twice as Colorado downed Washington, 5-1, in the opener of a three-game series.
Pomeranz (1-3) allowed one hit and a pair of walks while fanning six over 6 1/3 scoreless innings. Strasburg (9-4) was pulled a third of a frame earlier after giving up eight hits and two earned runs with six strikeouts.
"It's your mindset to limit runs anyway, but you know that it's going to be tough to score some runs off of him because he's a good pitcher," Pomeranz said about going up against Strasburg.
Colvin ended up with three hits and three RBI and Dexter Fowler also homered for the Rockies, who won for just the second time in their last seven.
Ryan Zimmerman's homer in the ninth was one of only five hits for the Nationals, whose four-game win streak came to a halt.
Zimmerman's blast came off of Rex Brothers before Michael Morse doubled and Adam LaRoche singled and advanced to second on defensive indifference.
Though it appeared the Nats were heading towards a second consecutive ninth- inning rally, Ian Desmond fanned, pinch-hitter Roger Bernadina lined out, then Jesus Flores popped out to end the game.
Colvin's one-out solo homer in the second put the Rockies on the board. Colvin struck again in the fourth, after Carlos Gonzalez worked a leadoff walk, and launched a two-run blast.
Fowler added a solo shot of his own with two down in the seventh. In the eighth, Michael Cuddyer's sacrifice fly brought in Gonzalez, who doubled to lead off and stole third before scoring.
Pomeranz held the hosts to one hit over the first six innings, a leadoff single by Bryce Harper in the fourth. He departed after fanning LaRoche in the seventh, then Matt Belisle retired the next two batters.
Belisle and Brothers combined for a scoreless eighth.
"It was just an off night all the way around. I think everybody in there got pitches to hit and we did nothing with it," said LaRoche.
Pomeranz threw 53 of his 81 pitches for strikes...Colvin recorded his second multi-homer game of the year, after doing so on June 9 against the Angels...Washington Capitals head coach Adam Oates threw out the first pitch...Zimmerman has hit five homers in his last 12 games...Rafael Betancourt notched his 14th save...Game-time temperature was 96 degrees.