PITTSBURGH -- Mitch Keller slammed a towel in the Pirates’ dugout Saturday as the grounds crew came out to place the tarp on PNC Park’s diamond.

He wasn’t ready to be done for the day, but he was at the mercy of Pittsburgh’s May showers. After the start of the game was pushed back nearly half an hour, this second stoppage would also be 30 minutes, which was cutting it close for manager Derek Shelton.

"I think if it would've been any longer, five or 10 minutes longer, it would've not been him [pitching the sixth],” Shelton explained. “We've got to be careful."

There’s plenty of reason for the Pirates to be careful with Keller, who signed a five-year deal this spring to be the long-term head of a young rotation. He showed on the field why the Pirates trust him to be that leader, too. Shelton went back to Keller in the sixth, hoping to get three outs from him. Keller gave five, finishing his day with 6 2/3 innings of one-run ball to clinch a series win over the Braves with a 4-1 victory.

“That's the story of the game,” Shelton said. “How sharp he was, but [also] going out and getting us five outs."

During that delay, Keller wasn’t paying attention to how much time had passed. He was doing some light tossing, hoping his day didn’t end after five innings. When he did return to the mound, his first pitch registered at 95 mph, quelling Shelton’s concerns.

“You just have to stay locked in,” Keller said. “Whatever it takes. The hardest one is the mid-game delay. Before the game, that's fine, whatever. You can still have your routine. I've never done that before. Just trying to stay hot. Going to warm up again is crazy, but it is what it is. You've got to find a way."

Keller tossed a 1-2-3 sixth and retired the first two hitters of the seventh before plunking Zack Short on a two-strike offering. Shelton turned to Colin Holderman to retire Ronald Acuña Jr., and after Holderman’s four-out appearance, David Bednar picked up his 11th save of the season.

The defense played its part behind Keller, with Bae’s fourth-inning robbery of Marcell Ozuna being the highlight of the game. Bae and Nick Gonzales sparked the offense to give him some wiggle room. But when facing a lineup with as much firepower as the Braves, you need pitching, and Keller has been in a groove.

While Keller’s April wasn’t exactly terrible, it wasn’t up to the same standard as his All-Star campaign in 2023, finishing with a 5.18 ERA. In four starts in May, he is 4-0 with four quality starts and a 1.30 ERA.

"I think just filling the zone up, attacking guys,” Keller said on what’s working for him this month. “Getting ahead and staying ahead. Using the full mix of my arsenal. I've got a lot of pitches, so the more I can use it, the more it keeps them off balance. Just executing strikes and using it all."

The Pirates’ rotation has enjoyed a boost by adding Paul Skenes to go along with the continued growth of Jared Jones and Bailey Falter. In the same way hitting is contagious, the same applies for starting pitching.

"I think when you have a solid rotation with Jared, Skenes, Falter and Martín [Pérez], we're all pretty close,” Keller said. “We're all pulling for each other and that makes it a lot more fun. We give each other feedback, what we see. … We're all pulling for each other. It's a cool thing we've got going."

But when Keller is clicking, he’s still the one leading this rotation.

“Whenever he's on the mound, we're always trying to play a winning game,” said Bae, via interpreter Daniel Kim. “It's a confidence boost.”