Sean Marshall gave the Chicago Cubs some hope with his second sparkling start at Minute Maid Park.
The rookie allowed six hits and struck out two in seven strong innings to help the Cubs beat the Astros 1-0 on Wednesday night, averting a three-game sweep.
Oswalt struck out six and scattered eight hits in what manager Phil Garner said was the ace's best start of the season.
The loss seemed to be the only thing that mattered to Oswalt afterward.
"You do all you can do," he said. "Hopefully, it will turn around sometime."
Oswalt, a 20-game winner the past two seasons, hasn't earned a victory since beating the Cubs 5-4 on June 14. He has only two wins since May 3, getting no decisions in five of his last seven starts.
The Astros had scored at least seven runs in their last four games, but Oswalt thinks his teammates tighten up when he pitches.
"I think sometimes they try too hard," Oswalt said. "Instead of just swinging at the ball, like nobody's on, they try to feel for the ball and try to do something with it instead of just swinging."
Marshall allowed only singles to Craig Biggio and Burke until Jason Lane doubled with one out in the fourth. It was Lane's third hit in 17 at-bats, but he was promptly tagged out on Eric Bruntlett's weak grounder back to Marshall.
Walker's double to the wall scored Michael Barrett, who singled with one out. Preston Wilson quickly fielded Walker's liner to the gap and Bruntlett had a chance to throw out Barrett, but his throw home was well off target.
The Astros had plenty of chances to tie it.
They stranded two runners in the first, third and fourth and then loaded the bases with two outs in the fifth. But Lane flew out to Juan Pierre at the wall in left-center.
Biggio led off the sixth with a double off the left-field wall. Burke bunted him to third, but Marshall retired Ensberg and Lance Berkman on ground outs.