Oswalt walked three and loaded the bases in the first. He allowed just one hit and struck out two while throwing 44 pitches, 25 for strikes.
The right-hander said he stuck to fastballs and changeups. He plans opening up his pitch repertoire a bit more in his next outing.
"The first inning was a little erratic, but it felt good though," Oswalt said. "I know the pitching coach is probably saying my mechanics are a little bit off. I was flying open a little bit to the left. I was actually trying to do that. Last year I got so conscious about staying in line toward the plate that I started cutting the ball and losing a little bit of late life. This spring I'm actually trying to work on going to the left a little bit to get through the ball a little more."
Oswalt is coming off the worst statistical season of his impressive nine-year career. He went 8-6 with a 4.12 ERA in 2009. It was the first time he hadn't posted double digit wins. He set a franchise record for no-decisions in a single-season with 16.
"If they score one more run we'd be in good shape," Oswalt said of all the no decisions. "It would have been 16 wins, put that up to the eight I had and it would have been 24. I wouldn't be called old anymore. But that's baseball. I know a lot of guys feel like they have great years and the numbers don't show up
"It's just one of those years where you wipe it to the side and start over."
The Astros are hoping their ace returns to the dominant form of 2004 and 2005 when he won 20 games in back-to-back years while leading the Astros to two straight NLCS and the franchises first trip to the World Series.
Longtime teammate Lance Berkman, who made his first start of the spring at first base, firmly believes Oswalt will have a resurgent 2010.
"I'd be surprised if he didn't win 17 to 20 games," Berkman said. "He's going to be right back to where he's always been."
Braves outfield prospect Jason Heyward extended his streak of reaching base to five straight games thanks to a walk in the first and a double in the fifth.
"He's been outstanding every ballgame," Braves manager Bobby Cox said. He's done something good whether it's base running, catching the ball or hitting it or taking walks. He's very, very impressive."
Heyward and center fielder Nate McLouth had the Braves only two extra base hits. McLouth led off the game with a double center.
Braves starter Kris Medlen surrendered one hit and two walks in two scoreless innings of work. He walked Carlos Lee and Berkman and gave up a single to Pedro Feliz to start the second inning. However, he got Geoff Blum to pop up to second and then got out of the inning with a 5-4-3 double play ball from Humberto Quintero.
Astros closer candidate Brandon Lyon threw a 30-pitch side session off a bullpen mound today and reported that his arm was feeling stronger. Lyon is a bit behind schedule this spring after he had a grape-sized cyst drained from his throwing shoulder this offseason. He has yet to make an appearance this spring .. The Braves' promising young starter Tommy Hanson will make his second start of the spring on Sunday when Atlanta returns to Disneys Wide World of Sports to host the Astros.