DENVER(AP) Ubaldo Jimenez 's dominating performance provided a much-needed respite for the Colorado Rockies ' tattered bullpen.

Jimenez pitched three-hit ball for eight innings and Carlos Gonzalez homered early, sending the Rockies over the Pittsburgh Pirates 8-0 on Wednesday night.

The night before, it was a different story. Colorado ran through the heart of their bullpen after Jhoulys Chacin , making his first career start in place of injured Aaron Cook (toe), lasted just 2 2-3 innings in a 7-3 loss to the Pirates.

''A performance like that from Ubaldo will straighten out the bullpen situation in a hurry,'' Colorado manager Jim Tracy said. ''It's beautiful, wonderful to say, and even better to sit out there and watch it take place.''

Jimenez said he was acutely aware of the bullpen's need for a break.

''I had it in my mind even before the game,'' he said. ''I wanted to go the distance, I had to throw seven or eight innings because most of those guys in the bullpen have been throwing a lot. I had to be out there for them.''

Jimenez (10-9) threw 119 pitches in his 20th consecutive outing in which he's gone six or more innings.

''I don't think there's too many pitchers in the American or National leagues that can go out there virtually every fifth day and do that,'' Tracy said. ''If there are, the list is very short. that is a real statement.''

Jimenez won his fourth straight decision in becoming the fourth member of the Rockies' rotation with double-digit victories, joining Jason Marquis , Aaron Cook and Jorge De La Rosa .

''He was hitting his spots pretty well,'' said Garrett Jones , who had one of the Pirates' three singles off Jimenez. ''You're looking for the fastball and you get it, but he's elevating it at the right time. He's throwing it 97, 98 mph, and he's throwing it at the letters, it's hard to square that pitch up. He was tough today, hitting his spots and mixing it up good.''

The Pirates finished with four hits and lost for the ninth time in 10 games.

Jimenez faced the minimum through three innings and worked out of his only serious jam in the fifth. He issued a one-out walk to Andy LaRoche and then Brandon Moss , who singled twice off Jimenez, followed with a hit up the middle.

A two-out walk to pitcher Kevin Hart loaded the bases, but Jimenez got Andrew McCutchen on an inning-ending groundout.

Hart (3-2), in his second start since being acquired by the Pirates from the Chicago Cubs on July 30, allowed five runs and eight hits in 5 1-3 innings. He ended a three-start winning streak he had built while with the Cubs.

Seth Smith singled to open the Colorado first and Gonzalez followed with an opposite-field drive over the fence in left. It was the second homer in as many days for Gonzalez, who increasingly is making his presence felt following an early June recall from Triple-A Colorado Springs.

Gonzalez has hit .412 (21 for 51) in the second half. Over his last five starts in which he's moved up to the No. 2 spot in the batting order, he's gone 9 for 23 (.391) with six runs scored and two homers.

The Rockies went up 3-0 in the fourth, getting a boost from slumping Clint Barmes , who had four hits in his previous 58 at-bats (.069) before delivering an RBI single. He added an RBI double his next time up during a two-run sixth. Troy Tulowitzki tripled to start the inning and scored on Brad Hawpe 's double.

In the eighth, Chris Iannetta hit a two-run double and pinch-hitter Ryan Spilborghs had an RBI double.

Todd Helton went 0 for 3 with a walk to end his hitting streak at 16 games, one shy of his career high.

NOTES: Barmes' four previous hits were home runs. ... Before the game, the Rockies selected the contract of RHP Adam Eaton from Triple-A Colorado Springs and optioned Chacin to the Sky Sox. ... Rockies CF Dexter Fowler , who left Monday night's game with a left knee contusion, remains day-to-day. ... Pittsburgh placed RHP Evan Meek on the 15-day DL because of a strained left rib cage muscle and recalled RHP Steven Jackson from Triple-A Indianapolis.