Jose Reyes hit a solo home run for New York, which extended its season-high win streak to eight games. It is the first time the Mets have won eight straight since June 2006.
Martinez left the game with right shoulder stiffness. Before leaving he worked four shutout innings in which he allowed one hit and three walks. Muniz (1-1) earned the win for the Mets after pitching two hitless innings.
Wagner had a perfect ninth to get his 22nd save.
Brad Hawpe got the only hit for the Rockies. Ubaldo Jimenez (4-9) was the losing pitcher after allowing three runs on seven hits and four walks in six innings with eight strikeouts.