Oswalt -- who requested a trade earlier this season -- allowed only a first-inning single to Neil Walker, Lance Berkman provided the power with two home runs and the Astros completed a three-game sweep of the Pittsburgh Pirates with a 2-0 win Thursday.
Oswalt has said he told his agent not to come to him until an offer was on the table and that he doesn't expect that to happen until after next week's All-Star break and closer to the July 31 trade deadline.
He was cagey when asked if a day like Thursday made him feel strange about the possibility of leaving.
"They pay you to pitch and that's what I'm going to do until it's time to go somewhere else," he said. "That's the business part of it. The best part about it is when you step across the white line and you don't have to worry about it."
Still, some in the Astros organization aren't convinced Oswalt, who has spent his entire career with the Astros, is going anywhere.
"I don't know that we need to start singing his swan song just yet with the Astros," Berkman said. "I'd say it's probably a long shot that he gets traded. I just feel that way. I'm not saying it won't happen, but I don't know that it's a great possibility."
Oswalt's seventh career shutout and 19th complete game finished the Astros' third sweep of the season -- second over the Pirates, the only team in the NL Central with a worse record than Houston. His last shutout came in September 2008 against Pittsburgh and his previous complete game was against the Los Angeles Dodgers last July.
The win breaks a career-long, six-game home losing streak for Oswalt (6-10). He struck out eight and walked two for his first victory at Minute Maid Park since April 23.
Oswalt didn't feel great early and was relieved to get through the early part of the game with only one hit.
"It was funny, the first three innings I was missing some spots here and there and was kind of getting nervous about not being able to throw where I want to," he said. "But at least I was missing them down in the zone, I wasn't missing them up. It seemed like when the fourth inning got there I slowed my mechanics down a little bit and was able to hit a few more spots later in the game."
Berkman has homered in four straight games for the first time since 2007 and has almost doubled his home run total for the season in that span. He had just seven homers before the current streak and Thursday was his 25th career game with more than one home run.
He credited some of his recent success to his left knee finally feeling almost as strong as it did before arthroscopic surgery in March.
"So maybe I'm getting a little more strength and seeing the ball a little bit better," he said. "It's subtle. It doesn't take much to be off. It's fractions when you're dealing with balls that are traveling at that speed."
The two solo shots came in the first and fourth innings and both landed in the Crawford Boxes in left field.
"He killed us," Pirates manager John Russell said. "He plays this ballpark very well. I've seen him do that countless times."
Carlos Lee singled and Pirates starter Ross Ohlendorf walked Hunter Pence after Berkman's second homer, prompting a short visit to the mound by Pittsburgh coaches. Ohlendorf (1-7) pitched out of trouble by retiring the next three batters, striking the first two out.
Oswalt allowed a single to Walker with two outs in the first inning and he walked Ryan Church with one out in the second. He then retired the next 12 batters before walking Andrew McCutchen with one out in the sixth inning.
After Jose Tabata flew out to center field, the Astros looked to have ended the inning when McCutchen was caught stealing at second. Players began trotting off the field before an umpire ruled Oswalt balked and McCutchen could stay at second. Astros manager Brad Mills briefly came out to argue the call but soon retreated and Walker grounded out to end the inning.
Oswalt pitched a perfect seventh before he was slowed briefly in the eighth inning when a ball hit by Bobby Crosby bounced off his right hand. Oswalt made the throw to first base for the out before a trainer came out to examine his hand. He made a couple pitches as Astros officials looked on before remaining in the game. He hit Jason Jaramillo with a pitch before striking out Delwyn Young and McCutchen.
Berkman made a nifty diving catch for the first out in the ninth to help Oswalt before he struck out the last two batters to complete the shutout -- the second one-hitter of his career. The first came in Sept. 6, 2008, at Colorado.
Thursday was the third time this season the Pirates have been shut out with Ohlendorf on the mound. He allowed seven hits and two runs with five strikeouts in seven innings.
"I feel like I've had three starts where I've thrown the ball well," he said. "Today my slider wasn't very good, but my fastball was coming off pretty well and I was able to rotate it well for the most part. I was able to get by with just using my fastball."
Play was halted briefly when a male fan ran onto the field in the bottom of the eighth inning. He went to the ground when a police officer approached and was led off the field in handcuffs without further incident. ... Houston right-hander Felipe Paulino, on the disabled list with right shoulder tendinitis, threw 30 pitches of live batting practice before Thursday's game. He said he felt good after the session and Mills said he is on schedule to return to the rotation after the All-Star break.