The Diamondbacks, trailing by two, turned to their bullpen at the bottom of the sixth inning.
Matt Adams might have made them regret the reliever they picked.
Arizona righthander Jake Barrett replaced lefty starter Robbie Ray, who surrendered two runs (one earned) on three hits. Barrett, who faced one batter at the end of Friday night's game, surrendered a solo home run to the Cardinals first baseman, the second batter he faced.
Adams' fourth knock of the season traveled 421 feet over the left center field wall and made it 3-0 Cards. The Redbirds entered game two off the National League lead for homers.