WASHINGTON (AP) -- Colorado manager Walt Weiss watched rookie pitcher Tyler Matzek battle the surging Washington Nationals on even terms into the seventh inning Wednesday night.
It was a good showing that went for naught when Weiss went to his bullpen.
After a replay review, Ian Desmond's solo homer off reliever Matt Belisle in the seventh inning provided the go-ahead run and the Nationals rallied from a three-run deficit for a 4-3 win over the Rockies and a sweep of the three-game series.
Matzek went 6 1-3 innings, allowing three runs on six hits in his fifth start. He struck out six and walked one.
"Honestly, when he started the game he didn't have his best command, best breaking stuff. He has lights out breaking stuff so he made some good adjustments," Weiss said.
"I think it was the fifth inning he started getting on top of his slider and started throwing his breaking ball with more angle and we utilized his changeup, which is his fourth best pitch, a lot more today."
Michael McKenry hit a three-run homer for Colorado, which has lost 14 of 16 and finished its road trip 1-6.
Matzek struck out the final three batters he faced -- the last being left-hander Bryce Harper - before Weiss brought Belisle (2-4) in to face the right-handed Desmond.
"I think (Matzek) got stronger as the game went on, but he was in uncharted territory," Weiss said. "He's a young guy that probably hasn't thrown more than 90, 95 pitches in the game."
Desmond's hit appeared to bounce off the top of the wall in right center, then off the railing in front of the first row and onto the field.
"I was just wondering what I was going to do if they messed it up," he said, "and luckily they didn't."
After a review that took 3:42, Desmond was given his 15th homer.
"It was a breaking ball that was up and out over, and Desmond got the barrel to it," Weiss said.
Jayson Werth also homered for Washington, which has won a season-high five straight.
Washington's Doug Fister (7-2) allowed three runs on seven hits over seven innings.
Rafael Soriano pitched the ninth for his 20th save.
The Rockies took 3-0 lead in the second.
Troy Tulowitzki and Corey Dickerson opened with singles. After Ryan Wheeler flied out, McKenry sent Fister's second pitch into the Nationals' bullpen for his first home run of the season.
"(Fister) likes to work quick and throws a lot of balls in the strike zone so I was kind of in the same mindset," McKenry said. "Just seeing a ball that I can get the barrel to and keep it simple."
Colorado hit the ball hard off Fister, but he limited the damage, finishing with five strikeouts and no walks while improving to 5-0 this season at Nationals Park.
Washington tied it in the fourth.
After Anthony Rendon singled and stole second, Matzek fell behind Werth 3-1. He left a fastball up and Werth sent it just over the center field fence for his seventh homer.
"Had a base open, 3-1 to a big hitter, that was a stupid pitch," Matzek said. "You just have to turn the page, move on, and get the next guy."
Harper followed with a bloop double to short left, went to third on a wild pitch, and scored on Desmond's single.
Colorado turned a highlight-reel double-play in the first.
With no outs, second baseman DJ LeMahieu made a sliding stop of Rendon's grounder behind second base and flipped it with his glove hand to shortstop Tulowitzki at second. Tulowitzki barehanded the toss facing center field, spun around and fired to first in time to get Rendon.
NOTES: The Rockies acquired RH Jair Jurrjens from the Reds for minor league first baseman Harold Riggins. Jurrjens, who was pitching at Triple-A Louisville, has a 53-37 record with a 3.63 ERA in seven major-league seasons. ... An MRI on RH Jhoulys Chacin's shoulder did not indicate a quick return from the DL. "It looks like he has some (rotator) cuff inflammation and we need to sit down with the medical staff and figure out a plan of attack," Weiss said. ... The Nationals are off Thursday, while Colorado hosts the Dodgers with LH Franklin Morales (4-4, 5.75) opposing RH Zack Greinke (10-4, 2.78).
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