MIAMI -- Needless to say Cardinals right-hander Michael Wacha didn't go through his typical routine prior to Monday's start against the Marlins.

Thanks to a 4 a.m. ET arrival Monday following a late game in Chicago on Sunday night, Wacha didn't fall asleep until about 5 a.m. His alarm clock woke him up at 2 p.m. so that he could eat, and he slept for another two hours before the team bus left a little after 4 p.m. for Marlins Park.

"I could've slept longer, easily, but I knew it was time to go to work," Wacha said.

And that Wacha did, as he outdueled former St. Louis prospect Sandy Alcantara in a 4-1 win over the Marlins in the series opener.

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Wacha pitched six scoreless innings in a triumphant return to the rotation, with his night concluding on his 75th pitch -- an 86.8 mph changeup to strike out Starlin Castro with two men on base in a four-run game.

Though Wacha's average fastball velocity was down (91.9 mph, compared to 92.6 mph) from this season per Statcast, he induced 10 groundouts, including three double plays. Monday marked his first scoreless start of six innings or more since June 3, 2018, against the Pirates.

"Pitched the ball down in the zone, got in on some guys, made them chase some balls out and away from there," said Wacha, who walked two and struck out four. "Just got some weak contact and let the defense play. That's how I've been successful in the past. Good to get back to it."

Another pivotal moment took place in the third, as the first two batters reached on a single and a walk. With Alcantara at the plate, Wacha picked off the lead runner after a replay review overturned the original call. Alcantara was unable to execute a sacrifice bunt and Austin Dean grounded out to end the frame.

According to Cardinals manager Mike Shildt, the daylight play was executed "on the fly" with Wacha and shortstop Yairo Munoz -- who started in place of Paul DeJong -- being on the same page.

"I just checked the field conditions when I tried to dive for a ball toward center field [earlier and] I slipped a little bit, so I knew it was going to be hard for him to get back to the base," Munoz said through an interpreter. "That's when I decided to give it a try. Of course, Wacha made an excellent throw. All the credit to him."

Wacha, who spent a little over a week on the injured list in late April with left knee patellar tendinitis, wasn't the same upon his return. Over five starts, he compiled a 6.39 ERA that lost him a rotation spot by May 22. Monday was his first quality start since April 17 -- his last appearance before the IL stint.

Twenty-two-year-old prospect Genesis Cabrera made two turns through the rotation in Wacha's stead, before an encouraging 2 1/3-inning scoreless relief outing last Tuesday against the Reds got Wacha the nod Monday.

“He looked like Wacha," Shildt said. "He kind of established himself. The last outing we saw in relief was very favorable. It gave us rightful confidence that he would get back out there, and he was tremendous tonight, really threw the ball well. There was life to his ball. The changeup worked, and just excellent job by Michael all around.”

With Adam Wainwright landing on the IL, and the starters struggling over the weekend in a series sweep to Chicago, Wacha's strong effort couldn't have come at a better time.

Asked whether Wacha's outing meant that he would start again Saturday against the Mets, Shildt said, "I think that's fair to say."

"It was important. It was important to solidify ... Michael to get back in that spot," Shildt said. "Create an opportunity for the rotation, but also it was important for our bullpen. We just got through three games in a row with not getting through the fifth inning. So it was important for that, and for Michael to reestablish and get back to being an anchor in our starting rotation.”