Wong got his first two major-league hits Monday night, keying a four-run rally with an infield single in an 8-5 win over the Milwaukee Brewers.
"That was a spark, that's what we talked about when we brought him here," manager Mike Matheny said of the rookie who was hitless in his first 10 at-bats after joining the team from Triple-A Memphis Friday night in Chicago.
"It was a pretty good example of what we were hoping for," Matheny said.
Wong had infield singles in the sixth and eighth innings, and stole two bases. St. Louis trailed 6-5 with two outs in the eighth when he hit a high chopper to third and was ruled safe at first by umpire Marty Foster in a call disputed after the game by the Brewers.
"That's what they brought me up here for, to get on base, so the guys behind me can drive me in," he said. "That's my goal. That's what I go up there every time trying to do."
The infield hit opened the flood gates. The single was the first of six consecutive hits, capped by pinch-hitter David Freese's two-run double, and the Cardinals won for the ninth time in 11 games.
"They were relentless right there," Matheny said of his team. "It started with some hustle with Wong legging that out, and guys having some big, big at-bats for us."
It didn't last long. The Cardinals erupted in the eighth off reliever Brandon Kintzler (3-1), who gave up four runs and six hits while getting just two outs.
Edward Mujica, who was unavailable during the weekend series at the Cubs because of a tired arm, pitched the ninth for his 32nd save in 34 chances.
Kintzler gave up a leadoff single to Molina, but Jay grounded into a double play. The Brewers reliever needed one more out to finish the inning, but gave up five consecutive singles to lose the lead.
The Brewers thought they should have been out of the inning after Wong's infield chopper.
"I was standing right there, and I thought he was out," Kintzler said. "But from his [Foster's] angle -- it's a short hop -- it's a tough call from his angle. I have a better angle. If you slow it down on replay, you have to really slow it down. It's a tough play. From his angle, it's tough."
Beltran singled, and Freese then hit the first pitch from Burke Badenhop for a double to make it 8-5.
The Brewers had two runners on in the ninth but Scooter Gennett grounded out to end the game.
Norichika Aoki hit his seventh homer for Milwaukee.
St. Louis starter Shelby Miller allowed two runs on five hits and four walks while striking out eight in 5 1-3 innings.
Milwaukee starter Marco Estrada allowed four runs on eight hits and a walk while striking out four in six innings.
Jay's two-run homer off Estrada in the sixth snapped a 2-2 tie. It was his seventh homer this year and second in two days after hitting a three-run shot in St. Louis' 6-1 win over the Chicago Cubs on Sunday.
Estrada said he threw a curveball -- a pitch he didn't want to throw -- to Jay.
"It's not frustrating to give up runs, it's going to happen, but it's frustrating that I threw pitches I didn't want to throw," he said. "I second-guessed myself and I got beat really bad on the one to Jay. I threw a pitch I didn't want to throw. There was no conviction behind it. I made the pitch and I got hurt."
Beltran snapped an 0-for-7 skid with his 21st home run in the first. He had three hits.
Brewers CF Carlos Gomez remained out of the starting lineup after spraining his right knee on Thursday night. Manager Ron Roenicke said he could play during the Cardinals series. ... Brewers 1B Juan Francisco struck out four times for the second consecutive game.