HOUSTON -- The ray of hope that the Astros flashed just last week dimmed significantly Wednesday afternoon, when they lost to the Cubs, 1-0, and got swept in front of 38,989 at Minute Maid Park.

That's right. Those same Astros, who came within a game and a half of the Wild Card lead a few days ago, have now lost five straight and fallen six games under the .500 mark.

"There's just no excuse for the way we've played over the last six games," catcher Brad Ausmus said. "We've got to do better than 1-5 against any two teams that come in here when we're trying to get to the top of the Wild Card race. It was a pitiful performance on our part."

The Astros haven't scored in their last 21 innings, though they had their fair share of chances in this three-game series against the Cubs. They left 36 runners on base and scored in only two of their last 36 innings.

"I don't know if I could put a barometer on how much frustration [we are experiencing] or if this is the most frustrated we've been, but it's up there," Ausmus said.

Hard times have certainly fallen upon the Astros, who took this one-run loss only hours after losing a heartbreaker in a Minute Maid Park-record 18 innings to the Cubs.

"It's frustrating just because it's another loss for us," said left-hander Andy Pettitte, who was saddled with a complete-game loss in this one. "We're on a little stretch here. I think we felt really good about ourselves a week ago, and now we feel terrible about ourselves again."

The Astros felt great about Pettitte's performance, at least. He escaped a bases-loaded jam in the first, and retired 15 of 16 batters before surrendering the game's only run on Michael Barrett's solo homer into the Crawford Boxes in the sixth.

Pettitte actually had Barrett down in the count, 0-2, but he left an outside fastball a little too far over the plate. And it cost him.

"You've gotta be extremely careful in this ballpark [with] a guy like him," Pettitte said.

Still, he only allowed the one run on four hits over nine innings. He also struck out seven batters and, more importantly, gave the Astros several shots at snapping their four-game losing streak.

Instead, the streak stretched to five as the Astros couldn't plate anybody.

"We've had good, determined at-bats," manager Phil Garner said. "We're just not getting any results, certainly not in the situations that we want. We're getting them on base and we're not getting them over."

The Astros put runners on, moved them over and brought them home during their winning stretch against the Padres, Diamondbacks and Pirates just a couple of weeks ago.

Now, they're back to square one and tied for third in the NL Central with the Brewers, whom they'll face in a four-game series beginning Thursday night in Milwaukee.

"Twenty-one innings of not putting a run on the board," Garner said, "I just gotta believe that we're going to break loose out of this."

Ausmus agreed, but he's still flabbergasted at his club's recent performance.

"We're going backward trying to accomplish our goal," he said. "The performances we've had over these last few days is frustrating. I know the fans are frustrated, I know [Garner's] frustrated, I know our front office is frustrated.

"It's no less frustrating for any single one of these players in here."

The Astros still have time to turn this season around. With 120 games in the books, they're somehow still lodged in the 10-team Wild Card race.

Sure, they'll have to leapfrog a half-dozen clubs in the standings, but they've got plenty of games remaining against divisional opponents.

And that leaves a little hope.

"I plan on making a run, and everybody else does," Pettitte said. "I feel like we're the best team in the Wild Card race. We just aren't playing like it."