Jonathan Herrera scored the go-ahead run on an eighth-inning passed ball Monday and the Colorado Rockies went on to a 3-1 win over the New York Mets. With the score tied 1-1, Herrera led off the eighth by laying down a bunt single, took second on pitcher Josh Edgin\'s fielding error on the play and went to third on Chris Nelson\'s pinch-hit sacrifice. With Charlie Blackmon at the plate, Herrera scored when Mets catcher Kelly Shoppach couldn\'t handle a pitch from Edgin (1-1). Ramon Hernandez added an insurance run with a ninth-inning RBI single and the Rockies hung on to claim the opener of a four-game series. Tyler Colvin homered to provide Colorado\'s other run. Rex Brothers (7-2) earned the victory with 1 1/3 scoreless relief frames. Matt Belisle got the final out of the eighth inning and Rafael Betancourt earned his 24th save despite allowing a hit and a walk in the ninth. Daniel Murphy got the only RBI for the Mets, who fell to a season-worst eight games under .500 (57-65).