DENVER -- Stephen Strasburg might wish he could face the Colorado Rockies more often.

The Washington right-hander again smothered the Colorado hitters, and Jayson Werth broke a tie with a two-run triple in the eighth inning Wednesday as the Nationals beat the Rockies 4-1.

Both teams scored runs on wild pitches, and the Nationals scored all their runs with two outs as they won back-to-back games for the first time since July 29-30.

The Rockies, who were held to a season-low two hits, lost for the eighth time in nine games and the 12th time in 16.

Strasburg (7-6) came off the disabled list Aug. 8, and he limited the Rockies to one run and three hits in seven innings with no walks and 12 strikeouts at Washington that day. While winning for the first time in three starts at Coors Field and picking up his 50th career victory Wednesday, Strasburg allowed one unearned run and two hits in seven innings. He struck out five without issuing a walk.

"He went out there from pitch one to the last pitch that he threw -- it was total control of the game," said Nationals closer Jonathan Papelbon, who earned his 20th save in as many chances and third with the Nationals since being acquired in a July 28 trade. "He knew exactly what he wanted to do and executed it."

In three starts since being reinstated from the disabled list, Strasburg is 1-1 with a 1.35 ERA, two walks and 25 strikeouts.

"He had an overpowering fastball and a real good changeup," Rockies manager Walt Weiss said. "We knew he was going to be tough. We had a real hard time with him a week ago, but he was every bit as good tonight."

Strasburg gave up a run in the second. Washington first baseman Ryan Zimmerman made an error on a ball hit by Ben Paulsen, allowing the Colorado first baseman to reach second base. Paulsen took third on a groundout and scored on Strasburg's wild pitch.

Strasburg retired 17 of the final 18 batters he faced, including the final 10, after Paulsen reached base.

"I think teams try to get me early," Strasburg said, "because I know when I get a feeling, when I start to settle down, command all my pitches, it's a little bit tougher."

Rockies starter Jorge De La Rosa pitched six scoreless innings, throwing a season-high 110 pitches in large part because of his season-tying six walks. He left the bases loaded in the sixth when he struck out Strasburg and departed with a 1-0 lead.

Gonzalez Germen came on in the seventh and gave up a two-out double to right fielder Bryce Harper, whose sinking line drive hit sliding center fielder Charlie Blackmon in the right leg. Germen walked third baseman Yunel Escobar on four pitches and walked shortstop Ian Desmond on five pitches to load the bases, then threw a wild pitch.

Rafael Betancourt (2-4) retired the first two batters he faced in the eighth before catcher Wilson Ramos singled and pinch hitter Clint Robinson walked, bringing up Werth. The Nationals left fielder was 8-for-47 (.170) with runners in scoring position and 3-for-23 (.130) with runners in scoring position and two out, but he lined an opposite-field triple to right.

Werth is still working his way back from a left wrist contusion that caused him to miss 61 games before he came off the disabled list July 28.

Moved into the leadoff spot Tuesday for the first time since April 2013, Werth went 2-for-5 with a double. After going hitless in his first two at-bats, Werth went to hit in the indoor batting cage in the Nationals' clubhouse, searching to replicate the feeling he had in batting practice. He connected on Betancourt's 1-1 fastball.

The win was just Washington's 11th in the past 31 games, and it nudged the Nationals over .500 at 60-59. They gained ground on the first-place New York Mets, who lost at Baltimore, but they still trail by 3 1/2 games in the National League East.

"We've got lot of hard work ahead of us," Werth said. "It's definitely going to be tough. We didn't do ourselves any favors, but it's all right there in front of us. We're just going to have to find a way."

NOTES: Rockies C Michael McKenry was placed on the 60-day disabled list with a lateral meniscus tear in his right knee. He will undergo surgery Monday. ... The Rockies selected the contract of C Dustin Garneau from Triple-A Albuquerque, where he was hitting .281 with 15 homers and 62 RBIs in 81 games. He has no major league experience. ... Colorado RF Carlos Gonzalez went 0-for-3 Wednesday. He left the Tuesday game after the fifth inning because of right knee inflammation. ... Rockies RHP Tyler Chatwood threw 20 pitches to hitters in his second simulated game and was fine. He is scheduled to throw 25 pitches to hitters Sunday as he continues his recovery from his second Tommy John surgery July 24, 2014. ... Washington 2B Dan Uggla (back spasms) began a rehab assignment with low Class A Hagerstown and went 0-for-2 while playing five innings. ... Nationals RHP David Carpenter (right shoulder inflammation) began his assignment with high Class A Potomac, allowing one run in one inning.