They'll likely need Lance Lynn to turn around his recent struggles in order to defeat the Brewers again Wednesday night, which would mark their first five-game winning streak since early July.
The Cardinals (84-60) wrestled control of the NL Central away from Pittsburgh over the weekend by winning all three meetings at Busch Stadium. Their division lead remained at one game after Tuesday's 4-2 win over Milwaukee coupled with Pittsburgh's 5-4 victory at Texas.
St. Louis was held hitless until Matt Holliday's two-run homer in the sixth inning. Fortunately for the Cardinals, starter Shelby Miller also turned in 6 2-3 shutout innings as they won for the 10th time in 12 home contests.
"We know what's at stake," Miller said. "We're watching the other teams, we're keeping up with it all. I think it makes it more fun for us."
The wins could continue to pile up with five more games to play on the current homestand, though they might need a bigger offensive night with Lynn (13-10, 4.37 ERA) on the mound.
He hasn't won since Aug. 4, going 0-5 with a 6.88 ERA in six outings, losing the last four and surrendering at least four runs in each of the last five.
Lynn gave up three homers for the second time in his career, accounting for three of the four runs against him over five innings of a 6-2 loss at Cincinnati on Thursday.
His winless stretch includes a six-inning effort in a 6-3 loss at Milwaukee on Aug. 20 in which he gave up six runs - four earned - and nine hits.
He faces a Brewers (62-81) offense without upstart rookie Khris Davis, who told the team's official website he likely won't return until Thursday at the earliest as he nurses a sore left wrist. Davis is hitting .298 with nine homers and 21 RBIs in 33 games since replacing Ryan Braun on the club's active roster but Tuesday marked the fourth straight game he's missed. Milwaukee is 24-24 in games in which Davis plays.
Pinch-hitter Logan Schafer produced the club's only runs Tuesday with a two-run homer in the ninth.
The Brewers will start Marco Estrada (6-4, 4.49), who has struggled against St. Louis, going 0-1 with an 8.14 ERA in four starts this year.
He's 2-0 with a 2.61 ERA over his last five games overall but will be pitching for the first time in 11 days, mainly due to the nature of Milwaukee's schedule. Estrada told the team's official website he tried to keep things similar, working through the routine he would normally use between starts twice during the layoff.
He's 1-0 with a 2.65 ERA in three games with six-plus days' rest this year and 3-4 with a 4.72 ERA in 12 such starts in his career.
"You're already in great shape (and) you've pitched through the season," manager Ron Roenicke said. "You should come back (from a longer layoff) feeling refreshed. Your arm should feel good, you throw two or three bullpens in between, and it should work out."
Yadier Molina is 12 for 21 lifetime off Estrada while Holliday is 6 for 18.