MILWAUKEE -- The St. Louis Cardinals' 5-1 loss to the Milwaukee Brewers on Wednesday may prove more costly than one defeat in the NL Central standings.

Cardinals starter Joe Kelly left in the middle of the fourth inning with left hamstring tightness after trying to reach base on a bunt.

"I felt like I tried to step a little quicker, maybe a little overextend and hit the bag a little bit before it and ended up tweaking it," Kelly said.

He was scheduled to return to St. Louis for an additional examination and treatment.

"I was feeling pretty good. I had three pitches working for me first time the whole year," he said. "I had a slider and a pretty good curveball breaking down, and had some velocity on my fastball and was locating it."

Kelly (1-1), who gave up an unearned run and three hits in four innings, did not know whether he would miss his next turn.

"If I miss my next start, I do," he said. "It's early in the year. It's best to be precautionary and go out and be healthy and go to my next one."

Wily Peralta (2-0) allowed one run and six hits in 6 1/3 innings, helping the Brewers avoid a series sweep.

Milwaukee, which entered the series with a nine-game winning streak, had one run and six hits in losing the first two games to St. Louis. The Cardinals won last year's season series 14-5.

"It felt good. That's a pretty good team over there," Jonathan Lucroy said. "They've had some momentum against us the last few years, so it was nice to get a win. To finish a homestand 4-2, that's pretty good. If we do that the rest of the year, we're going to be there at the end. They're a good team, a good club, but we're glad to pull one out against them on the last day."

After Kelly departed, the Brewers boosted their lead to 4-0 in the fifth against Seth Maness.

Wily Peralta reached base when his two-out liner went off the glove of shortstop Jhonny Peralta for an error. Gomez walked, Jean Segura hit an infield single, Lucroy followed with a two-run single and Aramis Ramirez had an RBI single.

Milwaukee went ahead in the third when first baseman Matt Adams misplayed Logan Schafer's leadoff bouncer for an error, Peralta sacrificed, and Carlos Gomez hit an RBI double to the wall in right-center, one pitch after bunting foul.

"That just goes back to prove the point that that's something we've got to bring every day," Cardinals manager Mike Matheny said. "We've got to bring that good defense. ... We've got the kind of guys who can make the plays. In games like this where we're not stacking up a bunch of runs."

Allen Craig hit his first home run of the season in the sixth inning off Peralta. Pat Neshek walked pinch-hitter Lyle Overbay with the bases loaded in the eighth for the Brewers' final run.

Will Smith, Tyler Thornburg and Francisco Rodriguez combined for 2 2/3 innings of scoreless relief. Thornburg retired three batters, extending his streak to 20 batters over six outings.

"I expect good things through this season," Brewers manager Ron Roenicke said of his bullpen. "We'll try to manage them right and make sure we're not using too many of the guys. I think Thornburg is stepping in, and what he's doing is huge."