Wainwright pitched a five-hitter and also contributed at the plate with an RBI double and a single as the Cardinals beat the Milwaukee Brewers 6-1.
"I don't think you can ask him to do anything else," St. Louis manager Mike Matheny. "What I really liked about tonight was just how sharp he was with his fastball. He really painted both sides and getting strikeouts with it."
Wainwright (9-10) moved closer to .500 after starting the season at 0-3. He threw 73 of 98 pitches for strikes, walking none and fanning seven.
All of Wainwright's strikeouts came during a stretch between the third and seventh innings when he retired 13 batters in a row. The complete game was his second of the season and 10th of his career.
"Any time you keep the bullpen out of it, you bring a win home for the team," Wainwright said.
"I was able to get ahead and finish guys off with located fastballs," he said.
Corey Hart had one of the Brewers' hits. He said Wainwright looked a lot like the pitcher he was before missing 2011 with Tommy John surgery.
"He's one of those guys that throws strikes," Hart said. "It's tough because you don't want to swing at every first pitch he throws, but he's not a guy you want to get beyond in the count with."
Ryan Braun drove in the Brewers' run with a sacrifice fly in the first.
After spotting the Brewers that 1-0 lead, St. Louis tied it when Beltran hit the first pitch from Mark Rogers (0-1) in the second just over the right-field wall. The ball bounced off the stands and back on to the field, and Beltran initially had to stop at third. After a one-minute review by the umpires, Beltran was awarded home.
The Cardinals broke it open by scoring four times in the third.
The Cardinals honored members of 1982 World Series championship clubs before the game and both teams wore retro jerseys. St. Louis defeated Milwaukee, then an American League team, in seven games in the Series that year. ... Brewers 3B Aramis Ramirez, who had a cortisone shot in his sore left wrist Thursday, was out of the starting lineup for the second straight game. . . . Marco Estrada will face the Cardinals' Kyle Lohse in the series finale Sunday. . . . Cardinals starter Jaime Garcia went 4 1/3 innings and allowed two hits and one run while striking out six in a rehab assignment for Double-A Springfield on Saturday night.