Wainwright looks to beat the Milwaukee Brewers for the second time in six days when the teams open a two-game series Monday night at Miller Park.

With 2005 NL Cy Young award winner Chris Carpenter recovering from elbow surgery and former 20-game winner Mark Mulder also injured (shoulder surgery), Wainwright (2-1, 2.78 ERA) is considered the Cardinals' (12-7) stand-in ace.

It may be too early to refer to Wainwright as a legitimate ace, but the fourth-year right-hander has built on a strong 2007 with three effective outings this season. He retired the first 11 batters in order and allowed one earned run in 7 2-3 innings Wednesday in a 5-4 victory over Milwaukee (11-7).

Wainwright has worked seven or more innings in six of his last seven starts dating to last season.

"I just think it's a credit to his mind-set," manager Tony La Russa said. "He's bound and determined to stay out there deep into the game. He just wills himself to keep going."

Wainwright, who is 2-1 with a 2.29 ERA in three career starts against the Brewers, has also contributed to St. Louis' success in another manner - with his bat. He is 4-for-8 with a home run and two RBIs this season, and is a .329 (25-for-76) career hitter with three homers and nine RBIs.

His third career home run came off Monday's scheduled Brewers starter Carlos Villanueva (1-2, 6.19).

"I feel like I'm going to get a hit every time," Wainwright said. "I'm sure I'll start seeing a slew of offspeed pitches here soon, and then we'll really talk about how I am as a hitter."

Wainwright will be asked to help the Cardinals avoid their season-high third straight loss. St. Louis lost its first series of the season over the weekend, falling 3-0 to San Francisco on Saturday before an 8-2 loss on Sunday.

The eight runs were the most allowed this season by St. Louis, which entered Sunday ranked second in the NL with a 3.07 ERA.

Milwaukee had a chance to complete a three-game sweep at Cincinnati on Sunday, but closer Eric Gagne, pitching for the fourth straight day, gave up back-to-back homers in the bottom of the 10th before Ken Griffey sealed the Reds' 4-3 victory with an RBI single.

"I felt very good," Gagne said. "I got behind in the count. That's the thing: You've got to get ahead. I didn't do that today."

The loss ended a three-game win streak for the Brewers, who went 5-4 on a trip to New York, St. Louis and Cincinnati.

"It seems like this road trip has lasted a year," manager Ned Yost told the team's official Web site. "It'll be nice to be home."

Villanueva had his worst outing of the season against St. Louis on Wednesday, allowing five runs and eight hits in 4 2-3 innings.

He is 1-2 with a 3.46 ERA in four career starts versus the Cardinals.

St. Louis' Albert Pujols is 7-for-18 (.389) with two homers and two doubles against Villanueva.