WASHINGTON -- Jhoulys Chacin did just about everything Saturday. He pitched an outstanding ballgame, drove in more runs than he allowed and even picked out Colorado's slump-busting attire.
DJ LeMahieu hit his first home run and Michael Cuddyer's RBI single in the first extended his hitting streak to 20 games, the longest active streak in the majors and tied for the longest this season. Nolan Arenado added a solo homer off Ross Ohlendorf in the eighth.
Chacin (6-3) held Washington to five hits with one walk and three strikeouts to win his third straight start. He also suggested to Rockies manager Walt Weiss that the team wear batting practice jerseys for the game.
"It was Jhoulys' idea. We were searching for something. We try everything," Weiss said. "So we went with the tops today."
Also new for Colorado, having rookie outfielder Corey Dickerson in the lineup. Making his major league debut, Dickerson doubled in his first two at-bats and drove in a run during a three-run first inning.
"Corey came in and gave us a shot there offensively," Weiss said. "Overall, we had a nice first inning and got things going, so it was a good day."
It was another bad day for Nationals starter Dan Haren (4-9), who allowed six runs and seven hits over 3 1-3 innings.
Haren, who signed a one-year, $13 million contract with the Nationals in December, struck out five but allowed his 19th home run of the season. He had two wild pitches and hit a batter with a pitch while raising his ERA to 6.15.
Ohlendorf allowed one run in 4 2/3 innings of relief. The loss snapped Washington's three-game winning streak.
Haren began the day leading the National League in home runs allowed, with six coming in his previous three starts.
"Same thing that's gone wrong the last few weeks," the veteran right-hander said. "Inability to get the ball down, putting us in a hole. It's the same story."
Seeing as that was about the only thing that went wrong for Colorado, expect another game with the new look.
"It's likely," a grinning Weiss said.
Cuddyer has reached base safely in 39 straight games, breaking the Rockies record set by Matt Holliday in 2007.
"Balls are just falling in," said Cuddyer, batting .349 since the hitting streak began on May 28. "That's just the way the game is going for me. At least once a day, it's finding the outfield grass."
After Cuddyer's RBI single scored Carlos Gonzalez, Dickerson, called up from Triple-A Colorado Springs on Friday, doubled with two outs. That scored Cuddyer and staked Chacin to an early 3-0 lead.
"I got a hit, too, but we started really good with three runs in the first so that gave me some support where I could go out and just throw strikes and get outs and throw a lot of innings," Chacin said.
After tossing consecutive 1-2-3 innings, Haren got wild again in the fourth. Facing five batters before being yanked, he allowed three hits, including Chacin's RBI single, threw a wild pitch and plunked Josh Rutledge, who later scored on LeMahieu's RBI single to make it 6-0.
Replaced following Chacin's hit, Haren walked to the dugout amid a torrent of boos from the crowd of 35,787.
"No one wants to be booed," Haren acknowledged. "I'd probably boo myself, too."
NOTES: OF Jayson Werth was scratched from the Nationals' lineup due to flulike symptoms, manager Davey Johnson said. Steve Lombardozzi replaced Werth in the lineup, while Roger Bernadina shifted from left field to right. ... Nationals OF Bryce Harper, who has been sidelined since May 26 with left knee bursitis, is not convinced he can begin a rehab assignment as quickly as his manager believes. Johnson had said Friday that he expects Harper to start a rehab stint Tuesday at Class-A Potomac, but Harper said on Saturday he thought he needed an extra day or two. ... St. Louis Cardinals 3B David Freese had a 20-game hitting streak earlier this season. ... Colorado LHP Jorge De La Rosa (7-4, 3.21 ERA) faces LHP Ross Detwiler (2-5, 3.34) in Sunday's series finale.