Lynn gave up one run on five hits and two walks in seven innings while matching the best win total in the major league this season. He struck out five and saw his earned run average drop to 2.75.
The Cardinals broke open a pitchers' duel between Lynn and Cincinnati's Homer Bailey (1-3) with a three-run sixth inning.
Bailey got the first out in the sixth but the next five St. Louis batters reached base. Allen Craig started the rally with a walk and Yadier Molina followed with a single. Matt Carpenter, Pete Kozma and Daniel Descalso had consecutive RBI singles that chased Bailey from the game and left St. Louis ahead 4-1.
Phillips finished the scoring with a lead-off home run in the ninth. It was his fifth homer this season.