HOUSTON – Phillippe Aumont had been the poster boy of the Phillies unexpected winning streak and unlikely entrance into the playoff race.

Just as the team that spent the majority of the season in last place wasn't expected to take off and make a legitimate run at a postseason berth in September, the big-armed but enigmatic reliever wasn't supposed to suddenly become Ryan Madson incarnate as the shutdown setup man in front on Jonathan Papelbon in his first month as a major leaguer.

But baseball games work in mysterious ways, as the Phillies and Aumont caught fire at the same time. Fires eventually burn out, of course.

After Tyler Cloyd was given an early hook on Thursday – he was lifted before recording an out in the fourth inning – Charlie Manuel turned to his born-again bullpen for six innings. He turned to Aumont for the fifth time in the last five days.

Aumont, who has had bouts of walking on the wild side throughout his rise in the minor leagues, hit a wall in the eighth inning in Houston.

Armed with a one-run lead, Aumont faced four batters. He walked two and hit a third, sparking Houston's three-run, come-from-behind rally in the Phillies 6-4 loss to the lowly Astros.

The loss snapped the Phils' season-high seven-game winning streak.

"I did feel like he was out of gas," Manuel said of Aumont, who he still felt was his best option at the time. "That's what we wanted. But when he got on the mound, the more he stayed out there, you could see he didn't have the stuff he had yesterday."

"I had to step up," said Aumont, who was making his third appearance in three days and fifth since Sunday's doubleheader. "I felt a little more tired than other days, but I have to be prepared for those situations."

In addition to ending the win streak, the defeat also briefly put a halt to the Phillies' climb to a National League Wild Card. The loss moved the Phils a game back of the reeling Pittsburgh Pirates for the seventh best record in the National League and 3 ½ games behind the St. Louis Cardinals in the race for the NL's second Wild Card.

The Cardinals played in Los Angeles late Thursday night against a Dodgers team that was one game back in the crowded NL Wild Card chase.

In the Phillies' unexpected and mad dash into that race, it's been the previously beleaguered relief corps that's held a starring role. The Phils bullpen hadn't allowed an earned run in 20 2/3 innings before Jake Diekman took over for Aumont and allowed a go-ahead, two-run double to Jed Lowrie.

After Cloyd was bounced from Thursday's game after serving up a three-run home run to Matt Dominguez before recording an out in the fourth, the bullpen was untouchable until the eighth.

B.J. Rosenberg, who entered the night with an 11.08 ERA, hopped in for Cloyd in the fourth and struck out two of the four batters he faced to start the pen's run. Rosenberg pitched a 1-2-3 fifth.

Josh Lindblom struck out two in the sixth before passing the baton to Antonio Bastardo. In the seventh, Bastardo posted his 10th straight scoreless appearance.

Bastardo has struck out 17 of the last 30 batters he's faced during that run.

"Bastardo is coming back," Manuel said. "He looks like he's getting his confidence back and he's throwing quality strikes."

The bullpen's resurgence in the last month has been nothing short of remarkable.

The Phils relief corps had a 4.72 ERA before the All-Star break, which ranked 15th in a 16-team National League. But in their last 25 games prior to Thursday, no relief corps in the league has been better.

Since Aug. 16, the Phillies bullpen had a 2.30 ERA.

"They've grown, and they've grown quick," Manuel said of his relievers. "They've come real good."

On Thursday, one of those arms endured more growing pains.

Aumont, armed with a fastball as big as his 6-7 frame, hadn't allowed a run in five straight appearances and appeared to nail down the eighth inning job on the Phillies 6-0 homestand.

But Aumont, who had a 6.9 walks-per-nine innings in 41 games at Triple A Lehigh Valley, couldn't locate the strike zone on Thursday. Only five of the 17 pitches he threw were strikes.

After a busy week, Aumont ran out of bullets.

"This is what I have to prepare myself for," Aumont said. "Tonight I felt like I was executing some of the pitches, I just have to focus more on keeping the ball in the zone and not trying to do too much."