The skies opened up and rain started peppering Wrigley Field.

Michael Busch didn’t even let the weather become a question mark.

The rookie first baseman hammered the first pitch of the bottom of the 9th inning into the right field bleachers and just like that, the Cubs were walk-off winners with a 3-2 victory over the Padres.

“It was fantastic,” Miguel Amaya said. “He didn’t want a rain delay.”

[WATCH: Busch breaks down his walk-off homer]

Most of the night belonged to a pair of star lefties — Shota Imanaga and Cody Bellinger.

Imanaga was masterful once again, giving Cubs fans déjà vu to the days of 2015 Jake Arrieta.

He tossed 7 shutout innings, carrying the Cubs on his back in a tense 1-0 game. Craig Counsell sent Imanaga back out for the 8th and disaster struck with a single just past Nico Hoerner and then a 2-run homer off the bat of San Diego leadoff hitter Jurickson Profar.

Those were only the 4th and 5th earned runs Imanaga has surrendered this season in his 7 starts. His season ERA now stands at a sparkling 1.08 ERA to go along with a 0.82 WHIP.

Bellinger, meanwhile, returned from a 2-week stint on the IL and immediately delivered with a 12-pitch at-bat in his first trip to the plate. He followed that with a home run and a pair of singles, almost singlehandedly jump-starting a Cubs offense that has been plagued by inconsistency in recent weeks.

Busch had been one of those Cubs hitters going through a bit of a down period with 6 strikeouts in his last 2 games entering Tuesday night.

Earlier in the game, he drilled a single to center before another whiff and a groundout.

But with a chance to win the game, Busch came up clutch.

“Right on time,” Bellinger said. “The rain was coming. ‘Atta boy, Buschy.”