PHOENIX -- Josh Collmenter is making the most out of being a relative unknown to the rest of the National League.

Collmenter pitched seven innings of three-hit ball and Stephen Drew had a three-run triple in the Arizona Diamondbacks' 4-0 victory over the Washington Nationals on Friday night.

"Getting back to basics, that's the key to my game, is being able to spot the fastball and work the off-speed stuff off that," Collmenter said. "We threw a lot of fastballs in, which I think resulted in a lot of those flare popups they couldn't really get the barrel of the bat to."

Collmenter (4-1) struck out five and walked one, improving to 3-1 with a 1.23 ERA in five starts since he entered the rotation last month. The 25-year-old rookie right-hander has pitched six or more innings in four of those starts.

"His changeup is outstanding and he mixed in a few breaking balls," Washington manager Jim Riggleman said. "With that quality of pitches, non-fastballs, the fastball says 86 (mph) but it feels like 94."

David Hernandez and Joe Paterson each got three outs to complete the three-hitter, Arizona's 17th victory in 21 games. The Diamondbacks (32-26) remained a half-game out of first in the NL West.

Yunesky Maya (0-1), making his second start of the season, allowed four runs and six hits in 4 1/3 innings for the Nationals.

Chris Young hit his 10th homer in the second inning, and Arizona chased Maya when it loaded the bases with one out in the fifth. Drew drove Doug Slaten's 3-0 pitch to the deepest part of Chase Field for his third triple of the season.

"I just told myself I'd get a good pitch. I did and I put a good swing on it," Drew said. "You look right down the middle, especially 3-0."

Collmenter helped set up the big hit with a leadoff walk. Ryan Roberts followed with a double, and Maya hit Justin Upton with a pitch with one out.

"The key at-bat was walking their pitcher to lead off the fifth," Riggleman said. "Nothing good is going to happen because you are turning the lineup over with no outs and what you hope would be an out to start the inning."

It was the longest outing of the season for Collmenter.

"Seven innings, we really needed it. Our bullpen's tired," manager Kirk Gibson said. "Even when he got behind he has the ability to throw a strike."

Game notes
Gibson said he thinks the play at home plate involving Florida's Scott Cousins and San Francisco catcher Buster Posey, in which Posey suffered a broken leg, was within the rules. "When it's a close play like that, you have no idea if that ball is going to be caught or if it's going to be mishandled. It's just bang-bang," Gibson said. "It's a baseball play. He (Cousins) chose to make sure the ball was dislodged and it's an unfortunate play." ... Nationals OF Jayson Werth was held out of the lineup after swelling and stiffness developed in his elbow that was hit by a pitch in Thursday night's game. Werth, who is batting .324 in his last 18 games, said he expects to play Saturday and will wear a pad over the elbow. ... Riggleman said 3B Ryan Zimmerman (left abdominal injury) played four innings in a minor-league game and is making progress. Zimmerman could be back with the Nationals by the middle of this month.