PHILADELPHIA -- After three days of watching the Colorado Rockies' offense jump out to big leads and cruise to easy victories, the Philadelphia Phillies knew they needed a strong day from the pitching staff to give themselves a chance in the series finale.

Although starter Vince Velasquez was able to give them only five innings as he struggled with his pitch count, a strong effort from a bullpen that's had its ups and downs gave the Phillies just the opportunity they needed.

A walk-off RBI single by Tommy Joseph in the 11th inning gave the Phillies a 2-1 victory over the Rockies at Citizens Bank Park on Thursday afternoon, ending the Phillies' five-game losing streak.

"I finally get to come in here and smile," Phillies manager Pete Mackanin said after what's been a rough month of May for the club. "Took 11 innings, but I'm happy we won."

That breakthrough came only after the Phillies squandered a pair of two-on, no-out situations, putting runners at first and second to open the fifth and eighth innings, but were unable to make anything happen either time.

Finally, against Colorado reliever Scott Oberg (0-1), Michael Saunders hit a one-out double and Joseph followed with his game-winning hit. Joseph hit his seventh home run for the Phillies' other run.

The loss closed out a 10-game road swing for the Rockies (31-18), who, despite losing in the finale, went 7-3 against Minnesota, Cincinnati and Philadelphia.

"We would have liked to win today and get the sweep and go back home on a win on a travel day," starting pitcher Tyler Anderson said. "We're playing good baseball...we'll go back home and try to do the same thing."

It wasn't a perfect outing for Velasquez, who gave up eight hits in his five innings while throwing 94 pitches, continuing a string of Phillies starters who have failed to get to the eighth inning in any game this season.

But he was saved by an outstanding performance from the bullpen, with six relievers coming in to two-hit the Rockies over six innings.

"The bullpen has really done a good job all series, but today they were stellar, all six of them," Mackanin said. "I said early on that was one of our strengths, and after today I think you can see why."

Jeanmar Gomez (3-1), activated from the disabled list earlier in the day, picked up the win by pitching a perfect 11th.

Oberg pitched one-third of an inning, giving up those two hits and taking the loss.

Joseph (2-for-5, two RBIs) was the main offensive reason the Phillies (16-29) were able to snap their losing streak, part of a larger stretch that saw them lose 20 out of their last 24 games.

"Today was a good step in the right direction," Joseph said. "Winning helps with a positive environment, and looking forward to building on it."

The Rockies' only score came in the fourth, when shortstop Trevor Story drove an 0-2 pitch from Velasquez into the right-field bleachers for his seventh home run of the season.

Anderson, who turned a forgettable April into a strong May, limited the Phillies to four hits through his first six innings. But he gave up a game-tying solo home run to Joseph in the seventh inning, and was removed after Cesar Hernandez's double led off the eighth.

The 27-year-old right-hander gave up six hits in seven-plus innings, striking out seven and walking two without receiving a decision. It was the fourth consecutive strong start for the second-year big leaguer, who had a 7.71 ERA through April but has a 2.55 ERA in four May outings.

"I just think throwing more quality strikes down, the ball's down, chances are it's going to go on the ground more often and give you a chance to keep going," he said.

NOTES: Thursday's loss was the first of the year for the Rockies in a one-run game. They had been 9-0 previously, the only team that had been undefeated in one-run games. . . . RHP Adam Morgan was sent down to Triple-A Lehigh Valley on Wednesday night. ...The Phillies and Rockies will not meet again until a three-game series in Colorado from Aug. 4-6, their only other time facing each other this season. ...The Phillies begin a three-game series against the Cincinnati Reds on Friday, with RHP Aaron Nola (2-1, 3.52 ERA) going against RHP Tim Adleman (2-2, 6.19 ERA). ...The Rockies return home Friday to start a three-game series against St. Louis. Rockies RHP Antonio Senzatela (6-1, 3.67 ERA) gets the start, opposed by RHP Carlos Martinez (3-3, 3.28 ERA).