Fielder homers, Brewers beat Cards 4-3 for sweep
Fielder's 19th home run chased Jake Westbrook (6-4) who carried a shutout into the sixth.
Rickie Weeks singled and scored on Mark Kotsay's double. Ryan Braun drove in Kotsay with a single before Fielder smashed the first pitch 440 feet into the second deck in right field for a two-run homer. It tied Fielder for the NL lead with Matt Kemp.
Fielder, who went 2 for 3 with a walk and two RBIs, now has 58 RBIs to extend his lead in the NL.
With the victory, the Brewers (38-28) took sole possession of first place for the first time since July 9, 2009. It moved them 10 games over .500 for the first time since they were 33-23 on June 6, 2009.
The Cardinals (38-29) had been in first since May 19, but have now lost four of the last five and were swept at Miller Park for the first time since April 30-May 2, 2007.
Fielder's eighth home run over the last 10 games helped Milwaukee improve its major-league best home record to 25-9. It also set a franchise record for the best start at home.
Shaun Marcum (7-2) won for the first time since May 21, a span of three starts that included a loss and then consecutive no decisions. He had never faced the Cardinals. He allowed three runs on five hits with eight strikeouts and a walk over seven innings.
Kameron Loe pitched a scoreless eighth.
John Axford converted his 15th straight save opportunity and 18th out of 20 overall in the ninth. He got a huge lift when Carlos Gomez, a defensive replacement for Kotsay in center, made a spectacular catch in the ninth. Gomez raced back at full speed and turned to catch Rasmus' fly ball just before crashing into the wall.
The Cardinals looked as if they might avoid being swept when Skip Schumaker hit a two-out, two-run single with the bases loaded for the first runs. Yadier Molina running from first had to duck as Schumaker's liner sailed over him and into right field.
St. Louis tacked on another run on Rasmus' double in the sixth.
Westbrook went five innings, allowing four runs and eight hits
NOTES: The Cardinals expect RHP Kyle McClellan (left hip flexor) and OF Matt Holliday (left quadriceps) to come off the disabled list this week. McClellan (6-2, 3.86 ERA) is scheduled to start on Wednesday against Washington. Cardinals manager Tony LaRussa said Holliday went through a full workout before the game and should be activated on Thursday. ... Cardinals 1B Albert Pujols went 0 for 3 with a walk and had his nine-game hitting streak snapped. ... Brewers manager Ron Roenicke said that when Milwaukee plays the Red Sox in Boston next weekend, Prince Fielder, Ryan Braun and Rickie Weeks might each take a turn at DHing.