DENVER (AP) -- Dan Haren was nearly unhittable for four innings. In the fifth, everything changed for the struggling right-hander.
Haren started strong but then faltered in his last inning, giving up five runs on two homers, and the Washington Nationals fell to the Colorado Rockies 8-3 on Tuesday.
It was another tough outing for the veteran, who is now 0-5 in his last six starts.
"I was kind of dumbfounded," manager Davey Johnson said. "He was really making pitches, he was cruising, and in the fifth he walked a hitter and seemed to lose the feel of the ball. Seemed like he couldn't locate it. It's tough. You can't mistakes in this ballpark."
Haren has struggled in his first season with Washington. He has not won since beating Detroit on May 9 to improve to 4-3, but he has shown glimpses of his past success during this recent bad stretch. He had allowed three runs or less in three of last six starts coming into Tuesday, but the lack of consistency has worn on him.
"I feel like I am letting the team down. It's not for a lack of effort, it's not for a lack of work and not for a lack of belief," he said. "I believe every time I step on the mound I'm going to win and I have to keep that feeling. I've been good for a long time, this is just a bump in the road."
Haren (4-8) appeared to have things straightened out early against the Rockies. He allowed just two hits and struck out five through the first four innings, but his first walk of the game, to Wilin Rosario to lead off the fifth, started his unraveling.
The next batter, Tyler Colvin, hit a high fly down the right-field line that landed in the seats just inside the foul pole that tied the game at 2-2. After a strikeout, Jordan Pacheco singled, Dexter Fowler doubled and Carlos Gonzalez hit a line-drive home run to left to give the Rockies a 5-2 lead.
He surrendered two more singles and faced 10 batters before getting the final out of the inning.
"Things were going well, made a couple of mistakes and just couldn't keep the ball in the ballpark," he said. "I'm getting strikeouts when needed for the most part, not walking guys but I can't keep the ball in the ballpark. That's what it comes down to. I've never had as much trouble with homers."
He was done for the night after allowing five runs on eight hits, one walk and striking out six.
"He had a low pitch count, I thought he was going to throw seven, eight innings the way he was throwing," Johnson said. "Then he started leaving the ball up."
The Rockies big inning made a winner out of starter Jhoulys Chacin, won for the first time since April. Chacin (4-3) allowed two runs on seven hits in five innings to end a string of four straight no decisions and three consecutive losses since his last win on April 19, when he pitched into the seventh inning to beat the Arizona Diamondbacks only to be forced out of that game by lower back tightness. He spent a couple weeks on the disabled list recuperating.
Colvin put the Rockies up 7-3 when he connected for a two-run shot in the eighth off reliever Drew Storen. It was his fourth career multihomer game and first since last July 6, also against Washington. The Rockies added a final run on Arenado's bases-loaded double-play grounder.
Washington took the early lead on Denard Span's two-run double in the second. Ian Desmond had an RBI single in the eighth to extend his hitting streak to career-high 13 games. However, the Nationals finished with eight hits, ending a season-high string of four consecutive games with double-digit hit totals.
Washington fell to 2-9 in its last 11 road games.
"We had opportunities but it didn't happen," Johnson said. "Tough ballpark."
NOTES: Nationals OF Bryce Harper will be re-evaluated in a week after getting a cortisone injection in his swollen left knee. He's also wearing a brace to ensure he rests the joint. ... RHP Stephen Strasburg, who's on the DL with a lat strain, threw a simulated game Tuesday and manager Davey Johnson said he came out of it well. Strasburg is eligible to come off the DL on Sunday. ... After the game the Nationals announced they traded RHP Henry Rodriguez to the Chicago Cubs for minor-league pitcher Ian Dickson.
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