WASHINGTON -- The way Tyler Colvin has been hitting lately, no pitcher appears capable of nullifying his torrid bat.

Not even Stephen Strasburg.

Colvin became the first player to homer twice off Strasburg in the same game, and the Colorado Rockies beat Washington 5-1 Friday night to end the Nationals' four-game winning streak.

Colvin hit a solo shot in the second inning and a two-run drive in the fourth. The first one came on a 0-2 fastball and the second on a 3-2 changeup.

"I got lucky right there," Colvin said. "He got two-strike counts on me and he gave me something I could handle and was able to put a good swing on it."

Colvin also singled in the sixth off Strasburg and hit a fly ball to the warning track against Ryan Mattheus in the eighth.

"This is a guy that we're very proud of," manager Jim Tracy said. "I don't know that you can swing much better than he's swinging it right now."

Over his past five games, Colvin is 7 for 16 with five homers and 10 RBI. This was his first appearance against Strasburg, but against Washington this season he's 10 for 17.

"If you throw a mistake, he's going to hit it just like any other guy in the league," Strasburg said. "For some reason, we've been making more mistake pitches to him than the other guys."

Dexter Fowler also connected for the Rockies, who had scored only nine runs in their previous five games. Drew Pomeranz (1-3) gave up one hit over 6 1/3 scoreless innings -- a bloop to center by Bryce Harper in the fourth.

Strasburg (9-4) allowed three runs, two earned, and eight hits in six innings. The All-Star struck out six and walked one, but lost a third straight start for the first time in his three-year career.

"It's not a good feeling, but what can you do?" Strasburg said. "You can only go out there and give it everything you have and try to keep the team in the ballgame, but sometimes it's not going to work out."

In his previous start, Strasburg lasted only three innings before being removed because of heat-related issues in Atlanta. In this one, his fastball reached 98 mph in 96-degree temperatures, and Colvin was more of hindrance than the weather.

"I thought he threw the ball well," Nationals manager Davey Johnson said. "He made two mistakes to Colvin."

Strasburg was outperformed by a pitcher on a last-place team making his 11th career start and in search of his third major league win.

Pomeranz walked two and struck out six against the team with the best record in the NL and an offense that scored 32 runs in its previous four games. His plan was simple: throw a slew of fastballs on either corner of the plate.

"I was locating it, putting it in the right place," the left-hander said.

Washington's Ian Desmond said, "I think a lot of guys are going to go home and dream about fastballs tonight."

It was Pomeranz's second start since being recalled from the minors. In his previous outing, he gave one run, none earned, and two hits over six innings in a 2-0 loss to San Diego.

"Not that he wasn't good last Sunday against the Padres, but tonight was spectacular," Tracy said.

Washington was blanked through eight innings and finished with five hits. In the ninth, after Ryan Zimmerman hit a solo homer off Rex Brothers and the Nationals got two runners on base, Rafael Betancourt got three outs for his 14th save.

Colvin put the Rockies up 1-0 in the second inning with a second-chance home run. After Washington catcher Jesus Flores dropped a foul popup for an error on Strasburg's first pitch to Colvin, the slugger drove a 0-2 pitch into the second level of seats in right field.

"Dumb pitch," Strasburg lamented.

With a runner on second in the Colorado fourth, Colvin masterfully worked the count from 1-2 to full before hitting the ninth pitch of the at-bat into the front row of the seats in right-center.

In the fifth, the Rockies got runners on the corners with one out before Marco Scutaro bounced into a 6-4-3 double play. One inning later, Colorado's Wil Nieves hit into a double play with the bases loaded and one out.

Fowler made it 4-0 in the seventh with his 11th home run, a drive off Tom Gorzelanny, and Michael Cuddyer added a sacrifice fly in the eighth.

Notes

• New Washington Capitals coach Adam Oates threw out the ceremonial first pitch.
• Nationals LHP Gio Gonzalez strives for his 12th win Saturday. The Rockies will counter with Jeff Francis, who's seeking to win a third straight start.
• Zimmerman has five HRs in his Past 12 games.