SAN DIEGO — Opening night was a smash hit for the Rockies’ C.J. Cron, who launched two homers, went 4-for-5, racked up 11 total bases and drove in five runs in a historic starring role. Charlie Blackmon, German Marquez and Elehuris Montero co-starred in Colorado’s 7-2 victory over the Padres on a chilly Friday at jam-packed Petco Park.