Rodriguez (1-2) gave up one run on three hits with three walks and seven strikeouts while Michael Bourn and Brett Wallace each had two hits and two runs scored for the Astros, who were coming off a split of a four-game set with San Diego.
Carlos Beltran’s solo home run accounted for the only run for the Mets, who have lost eight of their last nine. Jon Niese (0-3) gave up two runs on seven hits with five walks over six innings.
Houston struck in the first as Bourn led off with a single, moved to second on a sacrifice bunt then stole third before crossing the plate on a Carlos Lee single.
The fourth inning saw the Astros make it a 2-0 game as Wallace led off with a single and came home on a double from J.R. Towles.
Rodriguez, meanwhile, limited the Mets to just one hit and two walks through the first six frames.
In the seventh, with Sanchez on first, Lee ripped a shot to left that Scott Hairston misplayed and Sanchez crossed the plate for a 3-0 lead.
The Mets finally got on the board in the home seventh when Beltran led the frame off with a line-drive shot over the left-field wall.
Houston, though, padded its lead in the eighth on a bases-loaded balk from Bobby Parnell and a two-run single off the bat of Sanchez for a 6-1 advantage.
Jeff Fulchino worked around a leadoff double by Ike Davis in the ninth by retiring the final three batters to finish the game.
New York won four of the seven games against Houston last season…Houston batted 4-for-12 with runners in scoring position…Bud Norris is scheduled to take the mound for Houston on Wednesday and should be opposed by R.A. Dickey.