ST. LOUIS -- Whenever he’s called up to the big leagues, Lane Thomas takes advantage of learning from Dexter Fowler, whether it’s at the plate or in the outfield.

But on Sunday, Fowler said he could learn a thing or two from Thomas.

“Well I need to learn how to hit homers like him,” Fowler said. “He’s all ears, which is good. He’s always eager to learn, and he asks a lot of questions, which is awesome.”

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With the bases loaded and two outs in the bottom of the seventh, Thomas launched a grand slam 410 feet to give the Cardinals the lead in their eventual 11-9 victory, completing the three-game sweep over the Pirates. The insurance runs, and eventual margin of victory, came from Fowler’s two-run homer one inning after Thomas’ slam.

Thomas’ third home run of the year came after Pirates reliever Kyle Crick allowed two singles and hit two batters, which brought in one run and cut the Cardinals’ deficit to three.

On the seventh pitch of Thomas’ at-bat, Crick placed a 95-mph fastball high and inside on a 3-2 count, and Thomas made him pay, hitting it 103 mph off the bat and over the Pirates’ bullpen. Thomas had fouled off a slider in a 2-2 count earlier to keep the at-bat going and was preparing for the fastball.

“I knew he had walked and had trouble a few guys in front of me, so I knew he was going to throw a fastball,” Thomas said. “I tried to get ready for it and put a good swing on it.”

Thomas launched the Cardinals into sole possession of second place in the National League Central, two games behind the Cubs, and second in the Wild Card race, a half game behind the Nationals.

Fighting for playing time, Thomas hadn’t made a start since joining the Cardinals at the end of July, with Cardinals manager Mike Shildt opting for Fowler in center field and Tommy Edman in right. Shildt listed Edman’s switch-hitting ability as a reason for putting the infielder in the outfield lately.

But with many of the Cardinals’ everyday players getting a day off Sunday, including Fowler until he took over for Jose Martinez (right shoulder discomfort) in right field in the fifth, Thomas drew the start.

“Speaks to the kind of player that [Thomas] needs to be in a sense of where we are,” Shildt said. “He’s going to create more opportunities for himself, but with Ozuna back … he’s going to need to be a guy that can [fill in when needed].”

Thomas is learning how to prepare for any situation in any game. That can be challenging when a top prospect -- Thomas is the Cardinals’ No. 9 prospect, according to MLB Pipeline -- plays every day in the Minors

“It’s tough, especially when you’re used to playing every day,” Fowler said. “I remember when I got called up in '08, I don’t know how many at-bats I had, but they were sporadic. And they were against closers all the time. It was tough, but Lane’s done well and I’m proud of him.”

Thomas has embraced his role. He works with a high-velocity machine in the batting cage and trains with coach Willie McGee in the outfield on days he doesn’t start.

Although the grand slam was the most dramatic moment, it was only one part of Thomas’ eventful day. In the top of the first inning, he started a double play, catching Starling Marte’s fly ball in center and throwing out Adam Frazier at home. He almost had a diving catch in the at-bat before, but the ball slipped out of his glove as he hit the ground.

“Close, man,” Thomas said. “I’m going to have the trainers tighten the front of the glove. But yeah, close.”

And Thomas’ RBI triple tied the game in the bottom of the fourth. He finished 2-for-5 at the plate -- and was just a hair away from being 3-for-5 after he was called out on a close play at first in the bottom of the second.

Thomas’ game encapsulated the different ways he can help the Cardinals win.

“You look at Lane, and he’s definitely not the biggest guy, but he has a lot of power,” Edman said. “It sneaks up on you. Power, speed, he’s got everything. Really good defensive center fielder. Just watching him play the last couple of years, you know he’s going to be a big-time contributor.”

With the day he had and the Cardinals’ upcoming 16-game stretch in 17 days that takes them through Aug. 28, Thomas will likely find more opportunities to contribute on a team that is fighting for a playoff spot.

“Gives you a little confidence that you can handle whatever is thrown at you,” Thomas said. “Hopefully keeps going that way.”