CHICAGO -- The boos from the Wrigley Field crowd let the Cardinals know that fans were more than displeased with the decision. St. Louis opted to intentionally walk Kyle Schwarber in the fourth inning Saturday, loading the bases with one out.

Cubs catcher Taylor Davis quickly turned the reaction into raucous cheers.

Davis launched a first-pitch cutter from Cardinals righty Michael Wacha into a sea of red, white and blue in the left-field bleacher seats for a game-tying grand slam. The blast served as the catalyst for a 6-5 comeback win for the Cubs and gave Chicago's backup catcher his first career home run.

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"It's unbelievable," Davis said. "It was a really, really fun feeling hearing Wrigley Field react like that."

Javier Baez then had Wrigley shaking in the eighth inning when he belted a go-ahead shot to the right-field stands off Cardinals reliever John Brebbia. Following Baez’s trek around the bases for his 11th homer of the season, his audience erupted in chants of, “Javy! Javy!”

The pair of blasts canceled out the five runs allowed in a subpar start by Yu Darvish, who bowed out after walking the first two batters in the fifth. Chicago has now won 17 of its past 23 games to pull within a half-game of the first-place Cardinals in the National League Central.

Baez may have received the chants, but Davis was the story.

The reason for that is pretty simple.

"He doesn't surprise anymore," Cubs manager Joe Maddon said, of Baez.

But Davis?

"A very unlikely event right there," Maddon said with a chuckle.

The Cubs typically have Willson Contreras behind the plate, but Maddon opted to give the nod to Davis due to how well he worked with Darvish during the pitcher's previous start. The 29-year-old Davis is currently up from Triple-A Iowa to fill in for backup catcher Victor Caratini, who is on the 10-day injured list while recovering from left hand (hamate bone) surgery.

"Don't forget, Victor's on the way back," Maddon said. "Yes, we wanted to catch [Davis]. We liked the matchup with him and Darvish. As it turned out, he became more of an offensive catcher today, because Yu had such a tough day.

“But yes, we do have the depth there, and he's been really touted loudly by the guys upstairs. The analytical guys, for years, have really liked his work based on how he receives the baseball."

Davis was taken in the 49th round -- a round that no longer exists -- during the 2008 MLB Draft by the Marlins, but did not sign out of high school. Three years later, he signed as an undrafted free agent with the Cubs, making the gradual march up the organizational ladder.

In 2017, Davis finally got a taste of the big leagues with the Cubs, but his time in The Show has been limited to September promotions and filling in this year with Caratini shelved. Entering Saturday, Davis had a .217 career average in 16 games and 25 plate appearances in the big leagues. His only previous career extra-base hit came on Sept. 28, 2017, when he delivered an RBI double to score Schwarber in the 11th inning of a 2-1 win in St. Louis.

In the fourth inning on Saturday, Baez and David Bote reached with consecutive singles off Wacha, setting up a sacrifice bunt from Albert Almora Jr. The Cardinals' starter then intentionally walked Schwarber to face Davis -- a move that the fans did not like, but one no one questioned.

"They don't really know Taylor," Baez said. "So, it was a good decision, I think, even though Schwarber hitting a home run wasn't going to tie the game."

That led to the highlight of Davis' career to date.

"I was trying to execute a pitch down and away," Wacha said. "It just backed up on me and ended up in a bad spot."

Baez started celebrating at third base as soon as the ball soared off Davis' bat. The catcher's blond beard could not hide his smile as he touched the plate, where Baez, Bote and Schwarber greeted him.

"That was, like, perfect," Darvish said. "It looked like a movie."

After the game, reliever Brandon Kintzler joked that he could not get to his locker due to all the media around Davis. And, as the catcher spoke to reporters, his cell phone rang from a shelf behind him.

"It hasn't set in. I'll tell you when it does," Davis said. "But, at the end of the day, it's just one game, one swing."

It was much more than that.