PITTSBURGH -- Paul Goldschmidt has one of the most stoic demeanors in all of baseball. He draws a walk and takes his base quietly. He hits a homer and trots steadily around the bases. Despite all his success -- including six All-Star appearances, four Silver Sluggers and three Gold Gloves -- he tends to carry himself the same way in low times as in high times.

But the Cardinals slugger couldn’t hide his excitement after breaking out of a recent skid at the plate with a go-ahead grand slam in the top of the 10th inning to propel St. Louis to a 6-5 win over Pittsburgh in the series opener at PNC Park.

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Goldschmidt launched a 1-2 sinker from Pirates reliever Clay Holmes a projected 400 feet to right-center field, per Statcast, and he pumped his fist a bit and gave a grin as he rounded the bases before the visiting faithful erupted in chants of “Goldy! Goldy! Goldy!”

“I was just glad to come through right there,” he said of his emotion in the moment. “I just wanted to try to find a way to win, and that’s all it was.”

The first baseman was coming off a planned day off on Sunday -- though he entered to play defense anyway -- after he struck out seven times in three games against the Reds. Goldschmidt said he’d been trying to regain the consistency that gives him the eye-popping stretches he’s capable of putting up.

That didn’t appear early on, as Goldschmidt struck out two more times before he stepped to the plate in the pivotal 10th-inning at-bat. But he cleared his mind as he’s apt to do to focus on the task at hand.

“I do the best I can,” Goldschmidt said. “I’m human, but I think that was kind of the reminder going into that last at-bat or any time you’re struggling is, ‘Hey, you might get a chance your next at-bat.’ So it’s something I talk to myself a lot about, and tonight kind of showed exactly how that can happen.”

“A less mentally strong person doesn’t take that quality of at-bat late in the game with the bases loaded and one out,” manager Mike Shildt said. “You could see it. He kind of showed some determination, and just got down and gritty and put a short stroke on it.”

The game-winning slam was Goldschmidt’s 19th homer of the year and the fifth grand slam of his career. He swatted this one with his son, Jake, there to witness it, and the two came down on the field after the game, when the Cards’ fans broke out in one last “Goldy!” chant.

To get to that point, the Cardinals had to weather some heavy offense from the other side. Chasen Shreve, who stranded the winning run at second to send the game to extras, allowed consecutive doubles to Starling Marte and Josh Bell in the bottom of the 10th. Then Carlos Martinez allowed a two-run homer to Jung Ho Kang before the Bucs put two more runners aboard.

However, Martinez got out of it with a little help from his fellow Martinez -- Jose -- who cut down Kevin Newman as the tying run at the plate with an 88.9 mph throw from right field, per Statcast, that held up on review.

"I just threw the ball as hard as possible,” Jose Martinez said.

"What a play by Jose,” Shildt said. “Not a guy we typically get in there for defense late in the game in a close game, but based on where our pitching was, we had to be creative with our bullpen entering the game in the fourth inning. So we got him in there, and he's worked at it and he's continued to work at it, and he rewarded himself and us with a fantastic throw."

That throw helped Goldschmidt’s clutch grand slam stand up, but he’s not interested in the spotlight. Goldschmidt will take a win any way the Cards can get it, especially as they near the pivotal Trade Deadline in the middle of two four-game series vs. divisional opponents. And he thinks the key to keeping up this stretch of baseball, in which St. Louis has won eight of 11 out of the All-Star break, will be coming through when the game is on the line.

“I think we’re going to have to find a way to win these games,” he said. “There’s going to be the games you just lose, and there’s going to be ones you come out there and win. But we have to find a way to win the close ones.”