Freddy Sanchez follows the flight of his single that drove in the go-ahead run in the 11th inning of the Pirates' 4-2 victory over Colorado Monday night.

DENVER — For the third straight day, the Colorado Rockies had an eighth inning lead. For the third straight day, their bullpen couldn't hold it.

LaTroy Hawkins gave up a pinch-hit home run to Pittsburgh's Josh Phelps to tie the game in the eighth, and Brian Fuentes allowed a game-winning single in the 11th by Freddy Sanchez as the Pirates beat the struggling Rockies 4-2 on Monday night.

It was another frustrating appearance for Fuentes, who went on the DL in early July after blowing saves in four consecutive outings. No longer the closer, Fuentes struggled with command, facing five batters and walking one, hitting another and allowing a single.

"Command was the issue plain and simple for Brian Fuentes," Colorado manager Clint Hurdle said.

Fuentes was gone before the clubhouse doors opened and wasn't available for comment.

The Rockies opened a crucial seven-game homestand against the Pirates and Washington Nationals, two of the worst teams in the National League, and lost for the fifth time in seven games.

The Pirates' Cesar Izturis drew a leadoff walk off Fuentes (0-5). Nate McLouth bunted him to second and after Fuentes hit Matt Kata on an 0-2 pitch, Sanchez blooped an RBI single to short center field.

"Freddy had a great at-bat in the 11th, something he's done a few times in the past four or five days," Pittsburgh manager Jim Tracy said.

Said Sanchez: "Fuentes has some good stuff. I just wanted to put the ball in play and find a hole and the ball found a hole."

The Pirates added an insurance run when third baseman Garrett Atkins threw wildly on Adam LaRoche's two-out grounder, allowing Kata to score.

Damaso Marte (2-0) walked two, but retired pinch hitter Jamey Carroll in the 10th for the win. Matt Capps pitched a perfect 11th for his 12th save in 14 opportunities.

LaRoche went 3-for-5 with a pair of doubles. Josh Phelps hit a pinch-hit home run for Pittsburgh.

Troy Tulowitzki tied his career high with four hits, including his 16th home run. Brad Hawpe hit an RBI single as the Rockies lost for the fifth time in seven games.

Pittsburgh starter Matt Morris gave up two runs, but only one earned with seven hits in seven innings.