CHICAGO -- Astros manager Cecil Cooper called it perhaps his team's biggest win of the year, and considering all the things that went against Houston on Tuesday night, his words were certainly not an understatement.

After losing starter Roy Oswalt in the second inning to a back strain and having to send reliever Wesley Wright to the hospital with a possible case of appendicitis, the Astros were thrilled to escape Wrigley Field with a an 11-6 win over the Cubs that ended a three-game losing streak.

The win knocked the Cubs from first place in the National League Central, one-half game behind St. Louis. The Astros are in third place, 2 1/2 games out.

The Astros' 100th game of the year was anything but ordinary. In addition to the injuries, Wright and fellow relief pitcher Jeff Fulchino picked up their first Major League hits, and Fulchino had a comebacker to the mound get lost inside his jersey.

Other than that, it was a typical night at the ballpark.

"We just gutted it out," Cooper said. "This is probably the best win of the year for us."

Coming off a difficult 13-inning loss to the Cubs in Monday's series opener, in which they scored just one run, the Astros pounded out 17 hits and were 7-for-12 with runners in scoring position. Michael Bourn went 3-for-5 with three runs scored, Jeff Keppinger was 4-for-5 with three RBIs and Miguel Tejada was 2-for-4 with a homer and five RBIs.

"That's what we need to do," Tejada said. "We need to keep doing it for the next [62] games we have. Everybody needs to contribute, and if we do that we'll be a better team."

Geoff Blum's solo homer in the seventh inning snapped a 6-6 tie and made a winner out of Fulchino (4-3), who allowed three runs and three hits in three innings. The runs came on a three-run homer from Aramis Ramirez in the fifth that tied the score.

In that fifth frame, Kosuke Fukudome hit a one-hop grounder that got lodged inside Fulchino's jersey. Fulchino doubled for his first Major League an inning later.

"It was and up-and-down game," Fulchino said. "You didn't know how it was going to go, especially with Roy being out and being shorthanded. It turned out well. Personally, it was kind of an interesting start to my outing with the ball that hit me and went in my shirt, and the walk and three-run homer. I was able to recover from that and go two more [innings]."

Keppinger added a two-run triple in the eighth to make it 9-6. Tejada followed with an RBI single to score Keppinger. Chris Coste contributed an RBI single in the ninth.

"They brought it tonight, big time," Cooper said of his offense. "We got out and got the six runs early, and we needed some more and they were able to step up and do that. Everybody chipped in, and that's what it's about and that's the only way we're going to be able to stay in this -- is play good baseball."

Cooper had to use four relievers after Oswalt left in the second inning with a lower back strain. Oswalt will fly home to Houston on Wednesday to have his back examined by team doctors. Wright, who gave up three runs in 2 1/3 innings, was taken to a hospital after the game with possible appendicitis.

Tejada's sacrifice fly to center field -- caught by Fukudome at the wall -- gave the Astros a 1-0 lead, and Houston scored three times in the third to take a 4-0 lead. Keppinger, Tejada and Carlos Lee had RBIs in the frame, but the key play was an error by Cubs starter Ryan Dempster, who threw a ball into center when he had an easy out at the plate on Tejada's chopper.

"When [Oswalt] went down, that's the worst thing that can happen to us," Tejada said. "You see how the game went last night -- everybody was pitching. To lose him at this point of the year is not a good idea. Everybody needs to cross their fingers and hope he'll be OK."