Updated

Tyler Colvin hit a pair of two-run home runs to help the Colorado Rockies take an 8-3 win over the Washington Nationals in the opener of a three-game set.

Carlos Gonzalez smacked a three-run home run for the Rockies, who have won five of their last seven. Jhoulys Chacin (4-3) gave up two runs on seven hits with a pair of walks and strikeouts over five innings to get his first win since April 19.

"It's one thing to be here, but I know I can contribute to this team and help this team win," said Colvin. "Games like tonight justify why I am here."

Dan Haren (4-8) was tagged for five runs on eight hits over five innings for the Nationals, who won two of three at home against Minnesota over the weekend. Denard Span drove in a pair of runs and Ian Desmond added an RBI in the loss.

"This is a difficult place to pitch, but you have to be careful with the walks and there's a lot of room out there so the ball flys," said Haren. "But it's the same way for both teams so I'm not trying to make any excuses."

The Nationals grabbed the lead in the second inning as Span hit a two-run double to right field for a 2-0 lead.

Colorado had just two baserunners through the first four innings, but batted around in the fifth to surge ahead.

Wilin Rosario walked to start the frame and Colvin followed with his first home run of the year. Two batters later, Jordan Pacheco singled and Dexter Fowler followed with a double. After Nolan Arenado grounded out, Gonzalez turned on a 1-1 pitch and smacked it over the wall in left for his 18th home run of the season and a 5-2 lead.

The Nationals chipped away at the lead in the eighth as Jayson Werth led off with a walk, moved to second on an Adam LaRoche groundout and came home when Desmond punched a single to left for a 5-3 game.

Colorado, though, answered in the eighth on Colvin's second of the game, a two-run shot into the left-field stands. Arenado later grounded into a double play with the bases loaded for an 8-3 advantage.

Game Notes

Colvin, who made his first start of the year, has four multi-home run games in his career ... Chacin had been 0-3 in his previous seven starts and moved to 2-2 in four games against Washington ... Desmond has a 13-game hitting streak and is 17-for-50 during the run ... Haren is 0-5 over his past six starts and fell to 7-6 in 15 games against the Rockies ... After the game, the Nationals announced that they acquired pitcher Ian Dickson from the Chicago Cubs for pitcher Henry Rodriguez.