The right-hander's best outing this season followed a 20-2 shellacking Friday night, when the Phillies matched their largest run output this season with a 21-hit attack.
St. Louis got a two-run homer Saturday from Adam Kennedy in the bottom of the first and Ryan Ludwick's RBI single in the third. Kennedy was one of three players with two hits for the Cardinals, who ended a two-game skid.
Lohse (8-2) improved to 1-1 against his former team, despite striking out only three batters.
Closer Ryan Franklin recorded his ninth save, retiring the side in the top of the ninth.
Both Philadelphia runs scored on Pat Burrell's fourth-inning home run, his 18th this season and second in the three-game series.
The Phillies were limited to the four hits.
The losing pitcher was starter Adam Eaton (2-4).