St. Louis starter Jaime Garcia was pulled after three innings, replaced by Shelby Miller. Garcia allowed four runs and seven hits on the evening.
Pete Kozma put the Cardinals on top 2-0 in the second inning with a two-run triple, but it's been all Padres since.
San Diego tied it in the bottom of the second after an RBI single from Chris Denorfia and an RB -double from Logan Forsythe.
Cameron Maybin hit a two-run home run in the third and RBI singles from Jesus Guzman and Yonder Alonso put San Diego up 6-2 in the fourth.
Padres starter Eric Stults has given up two runs and three hits through five innings, striking out four.
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