In the opener, Adalberto Mendez pitched one-hit ball for six scoreless innings before injuring himself in his major league debut, and the Marlins won 7-1.
Oswalt (11-13) allowed four runs and six hits, striking out seven. The three-time All-Star is 5-1 since joining the Phillies in a trade with Houston on July 29. Philadelphia is 7-1 in his starts.