Curtis Granderson hit a pair of homers and drove in three runs for the Mets, who have won consecutive games behind the future of their pitching staff.
After Noah Syndergaard tossed two innings of one hit ball in his spring debut on Monday against the Atlanta Braves, Wheeler followed with another impressive outing by a young arm.
Wheeler, who made his major league debut last season and is slated to be in the five-man rotation for the Mets, allowed two hits and struck out three. Syndergaard, on the other hand, is expected to begin the season in Triple-A.
Jonathan Villar hit a two-run homer for the Astros, who saw starter Rudy Owens fail to get out of the first inning. The right-hander was charged with three runs on three hits with three walks in just 1/3 inning.