On cue, that old Blackmon magic showed up Tuesday night at Coors Field, but the Rockies’ chances of beating the Cardinals disappeared with the return of late-inning pratfalls. St. Louis scored a run in the seventh and four more in the eighth to turn a tight game into a 7-3 cruiser. A day after announcing his retirement, 14-year veteran Charlie Blackmon swung his magic wand and gave the Rockies a short-lived 3-2 lead in the fifth with an RBI triple into the right-center gap. Blackmon is 38, but he still has the wheels of a much younger player, and he burned up the basepath on his way to third.