Updated

Mexican-born lefty Jorge De La Rosa will try to get back on the winning track Sunday when the Colorado Rockies visit Nationals Park for the finale of a four-game series with the Washington Nationals.

The 32-year-old won five straight decisions between May 7 and June 2 to get to 7-3 on the season, but he's subsequently gone 0-1 in three starts, including a 5-1 loss to the Nationals in Colorado on June 12.

In that game, the sixth of his career against Washington, De La Rosa was nicked for four hits and three runs in 5 1/3 innings while falling to 3-2 against the Nationals with a 4.84 earned run average in 35 1/3 innings.

He took a tough-luck no-decision in his most recent start, allowing a single hit in seven scoreless innings at Toronto on June 17 in a game the Rockies lost, 2-0.

De La Rosa is 2-3 in eight road starts this season, 22-34 in 103 career road outings and has won both career starts at Nationals Park with a 5.73 ERA in 11 innings of work.

For Washington, lefty Ross Detwiler meets the Rockies for the fifth time in his career and the second time in 10 days.

The 27-year-old is 0-2 in his initial four meetings with Colorado, having most recently faced the Rockies on June 13 for a no-decision while allowing three runs on six hits in five innings of a game Washington won, 5-4.

Detwiler's last win came May 10, when he beat the Chicago Cubs with 6 2/3 innings of two-run ball in a 7-3 triumph.

In three starts since, including the game with the Rockies, Detwiler is 0-2 and has seen his ERA rise from 2.53 to 3.34.

He is 1-2 in four home starts in 2013 and 14-9 at home in his career with a 3.21 ERA in 210 innings of work.

On Saturday, Jhoulys Chacin threw seven scoreless innings to lead the Rockies past the Nationals, 7-1.

Chacin (6-3) scattered just five hits and walked one with three strikeouts for his third straight win, after going winless for more than a month.

"Another great outing by Jhoulys, he was really in control of the game," said Rockies manager Walt Weiss. "A good looking performance by Jhoulys."

DJ LeMahieu finished 3-for-5 with a home run and two RBI and Nolan Arenado had his own solo shot as well. Michael Cuddyer, Corey Dickerson and Chacin each contributed with an RBI apiece for the Rockies, who snapped a five-game losing streak.

Dan Haren (4-9) had his shortest outing of the season, going just 3 1/3 innings while surrendering six runs on seven hits. He hasn't won a game since May 9 and the Nationals are winless in his last eight starts.

"I've done video and changed the way I pitch," said Haren. "At this point I'm just searching on ways to get better."

Ryan Zimmerman's homer in the ninth accounted for Washington's lone run.

The teams met up last week in Colorado, where the Nationals won two of three.