Alex Bregman had batted in George Springer in the first. Lance McCullers Jr. had yet to give up the only run he surrendered in his five innings of work.
In the fourth, Astros outfielder Josh Reddick cranked a Mike Montgomery pitch over the right field wall for a two-run shot.
Two batters later, after Aledmys Díaz walked, and Maldonado launched another two-run blast, this one to right field.
It put the Astros up 5-0, with McCullers and Maldonado mostly dominating the Royals’ lineup in the bottom half of the inning.
The home run makes the highlights, but helping make sure McCullers mixed all of his pitches may have been Maldonado’s greatest contribution to the Astros’ 6-3 win.
“That’s how he’s had success in the past. We treated this like a regular season start,” Maldonado said. “So we were trying to mix pretty much every pitch every pitch of any kind.
“Changeup was really good. His one mistake went by (Salvador Perez, who homered in the fourth). Other than that, he got strikes on it, got a couple of punches on it. … I think he’s where he needs to be for the season to start.”
Astros manager Dusty Baker commended Maldonado’s performance behind the plate.
McCullers only shook off his signs a couple of times. The pitcher said Maldonado stayed on him about using all of his pitches, especially the changeup.
"I was really impressed with (Maldonado) and the way he called pitches tonight," McCullers said after the game. "How prepared he was, because us just getting here the day of (the game). He also went deep. He looked great. So it's great to see that."