If patience is a virtue to unlock power, Pete Crow-Armstrong showed that off in style on Wednesday afternoon.

The Cubs' top prospect (No. 25 in MLB) worked an incredible 16-pitch at-bat for Double-A Tennessee before launching a grand slam -- the first of his Minor League career -- to right field.

"Bases loaded, nobody out, you're just trying not to make an unproductive out," Crow-Armstrong said of his mentality with three runners on base. "I'm fighting up there, just trying to put a ball in the air to the outfield. I'm just trying to score somebody."

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Crow-Armstrong fell in an 0-2 hole after watching two pitches and fouled off a stunning 11 pitches, including six straight before the homer. Even more amazingly, he homered on a 2-2 count -- he didn't see three balls in the 16-pitch at-bat.

"As the pitch count gets higher in that at-bat, you kind of lose track of how many pitches you've seen. I think that at-bat specifically, I was seeing the ball well, but I probably could have had some better takes," Crow-Armstrong said. "Just trying to survive in that at-bat, and I took enough swings where I felt like I was going to get one good."

How rare is an at-bat that long, ending in a homer? Since pitch-count tracking began in MLB in 1988, only one player had a lengthier such at-bat. Alex Cora homered on 18 pitches (May 12, 2004), while Terrmel Sledge (July 7, 2004) and Jermaine Dye (May 22, 1998) also went deep on their 16th pitches. And none of those were grand slams.

Wednesday's grand slam was Crow-Armstrong's second long ball in three games, as he is showing newfound power early this season. Long known for his elite center field defense and plus speed, the 21-year-old is slashing .341/.375/.614 this season with a pair of doubles, triples, and homers.

"With better pitch selection, I'll start to see some more home runs on the board. But there's no conscious, 'I'm trying to hit a homer here,'" Crow-Armstrong said. "For me, it's about getting the right pitch and and just putting an 'A' swing on it as many times as I possibly can."

Crow-Armstrong has reworked his swing since arriving in the Cubs' organization via the Javier Báez trade in 2021, which helps him add more loft and pull -- as he did Wednesday. He hit a career-high 16 homers across two levels last year and is on pace to surpass 20 for the first time this season, especially if his discipline continues as he's shown lately.

"Michael Ryan, our manager, said this when I got back in the dugout -- he kind of yelled it -- he said 'Compete.' I think I'm trying to do that every at-bat," Crow-Armstrong said. "It's something we've really been preaching with this Tennessee team and throughout the organization -- swinging at pitches we're going to drive and do damage on."