ST. LOUIS -- Paul DeJong knew he needed to lock into the middle of the strike zone.

After a hot start to the season -- eight home runs and a .343 batting average -- the Cardinals' shortstop regressed heavily in May. He expanded the zone, chased some pitches and hit just .191 in the month plus five days of June heading into Thursday’s game against the Reds. DeJong needed a spark, and he knew it would come with his approach.

So when DeJong got ready for his at-bat in the bottom of the seventh inning against Reds reliever Michael Lorenzen, he took a piece of advice from first baseman Paul Goldschmidt: Lorenzen had been relying on his changeup recently. DeJong then saw Yairo Munoz line a changeup for a base hit right before stepping to the plate.

With the thought of protecting himself against a low-and-in changeup that might be used to get him to chase, DeJong locked into the middle of the strike zone -- and got a changeup down the middle. He took it past the wall in right field, jump-starting not only his offense but the Cardinals’ as well, as the two-run shot broke the tiebreaker for the Cardinals' 3-1 win at Busch Stadium.

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“[I] personally needed it, and our team needed it, so I was just happy to come through for the group,” DeJong said. “May was a tough month. It takes some mental toughness to overcome things like that. Being confident in myself to go out there and when that shows up in the middle, I’m ready to swing, ready to hit. Today was good for that, for my confidence.”

Right-hander Dakota Hudson held the Reds to one run in 6 1/3 innings of work, and the Cardinals worked their way around Reds’ right-hander Anthony Desclafani but couldn’t knock in as many runs as they should have. They went 1-for-9 with runners in scoring position until DeJong’s 388-foot home run.

It was DeJong’s ninth home run of the season, but only his first since May 18. He had gone 4-for-47 with one extra-base hit since. It was indicative of the Cardinals’ offense throughout that time, too, as the team struggled to score runs and win games.

Manager Mike Shildt tried moving around the lineup, switching DeJong to second and Goldschmidt to third, for the series against the Cubs. While the Cardinals swept that series, DeJong still grappled with his at-bats.

DeJong doesn’t remember a slump like that in his baseball career, but he didn’t look at the stats as he worked through it. His focus was on the next at-bat, the next pitch and his approach for all of it.

A start like DeJong’s doesn’t come without pitchers adjusting and trying to pitch around him as the season wore on. Shildt noticed DeJong staying patient through that adjustment -- although DeJong countered with probably too much patience as he expanded the zone, and became anxious when he knew he missed a pitch to hit.

“His walks had increased, his strikeouts decreased,” Shildt said. “He’s a patient guy. He’s been chasing around the perimeter of the zone a little more than he’d like, but he got a pitch he could put a swing on and did damage. Big swing.”

One swing can revive a player’s game, and one player can spark a team. That’s what DeJong did Thursday, and he said he’ll try to ride it as long as he can.

“It’s just like Babe Ruth said: Yesterday’s home runs don’t [win today’s game], so tomorrow I’ll be ready against the Cubs,” DeJong said. “And we’re going to try to win a game.”