Paul DeJong and Matt Carpenter hit home runs in a five-run second inning as the Cardinals blanked the Royals 7-0 in Kansas City.
Harrison Bader also homered and Jose Martinez had three hits and two RBI for St. Louis.
Austin Gomber allowed four hits over five innings for the win. The Cards have won five-of-six.
Burch Smith surrendered five runs in an inning-and-two-thirds to take the loss for KC.
Lucas Duda and Brett Phillips had two hits each for the Royals, who have lost seven-of-eight.