ST. LOUIS — There's a case to be made, perhaps even a convincing one, for adopting the designated hitter rule in the National League, for taking the bat out of the hands of players who are not particularly qualified to swing one.

It's debatable, too, whether the Twins are foolish to seek out aging pitchers near the end of their career, that their recent experience in signing J.A. Happ or Homer Bailey should discredit the strategy forever.

A counterpoint exists to both arguments, though, as the Twins learned Sunday. And his name is Adam Wainwright.

"He's very good at what he does," said Twins manager Rocco Baldelli, who was drafted on the same day in 2000 as the St. Louis righthander.

Wainwright, 1-for-33 at the plate this season, added to his major league lead in sacrifice bunts on Sunday by twice moving up runners. But the 39-year-old also contributed the most compelling at-bat of the Cardinals' 7-3 victory over the Twins, one that gave St. Louis a lead it never relinquished.

"It's not Wainwright's first go-around," Baldelli said of a .191 career hitter with 10 home runs. "He can handle the bat a little bit. That was a big moment in the game."

And on the mound? Wainwright was as steadfastly efficient as ever, using a fastball that rarely reaches 90 miles per hour to limit the Twins, who have lost six of their past eight games.

It was exactly the sort of performance — and as his 3.53 ERA proves, a pretty standard-issue one this season by the three-time All-Star — that Twins decisionmakers must have believed they would receive from their own veteran pickups in last winter's free-agent market. Wainwright, too, was a free agent, and re-signed with St. Louis one week afterfor the same $8 million guarantee that Happ received. Ouch.

Wainwright looked worth that investment for his pitching, but it's his bat that brought the announced 28,975 at Busch Stadium to their feet Sunday. Two quick outs in the fourth inning allowed Michael Pineda to relax, but Tommy Edman's double extended the inning. No problem, though; the Twins simply intentionally walked Edmundo Sosa to bring automatic-out Wainwright to the plate.

Except it wasn't automatic. Pineda got behind 2-1, and then started pumping fastballs in the 85-degree heat and humidity, which Wainwright gamely fought off. Pitching coach Wes Johnson visited the mound to reassure and encourage Pineda, but Wainwright kept battling. Pineda threw only three pitches all day that exceeded 93 mph, all of them to the opposing pitcher.

"The longer the at-bat went, the more comfortable he got, the better swings he was putting on the bat," Baldelli said. "You're not really expecting that kind of competitiveness out of the [pitcher]. That at-bat ultimately put them in position to win."

That's because, with the crowd roaring, Wainwright turned on Pineda's 10th pitch and hit a one-hop line drive directly to Luis Arraez. The third baseman speared it, took his time to set himself — and threw the ball in the dirt to Miguel Sano, who couldn't keep the baseball in his glove. Edman scored to tiebreaking run, the standing ovation hit its crescendo, and Wainwright patted Sano on the back at first base.

"That at-bat actually motivated me to keep competing," said Pineda, who grounded into a inning-ending double play in his only time at-bat. Pineda didn't get to keep competing, though, because Baldelli used Jake Cave to pinch hit for him in the fifth inning.

BOXSCORE: St. Louis 7, Twins 3

The Twins bullpen, spotless on Saturday, wasn't as good a day later; all three relievers gave up runs as the Cardinals pulled away. A wild pitch by former St. Louis righthander John Gant, acquired by coincidence for Happ on Friday, added to the lead, and Sosa singled home a run off Danny Coulombe an inning later, then homered off Beau Burrows in the eighth.

The Twins, who took an early lead on Andrelton Simmons' two-run single, never threatened again after Wainwright's at-bat, with only a Jorge Polanco home run narrowing the Cardinals' final margin.