KANSAS CITY, Mo. – This Twins team that's making a focused charge toward the postseason isn't the same one that started the season. And probably no game illustrated that transformation better than a more-difficult-than-it-looked 8-5 victory over the Royals.

Ervin Santana, who retired eight of the first nine hitters he faced Friday, who eventually walked away with his AL-leading 15th victory, still wasn't quite as dominating as Paul Molitor expected. So the manager abruptly ended his night after just 67 pitches, and turned a tight game over to his still-new-to-all-this bullpen.

Could anyone imagine such a decision two months ago? But Trevor Hildenberger made it work.

The rookie sidearmer "is a hot hand, and we're riding it," Molitor said after summoning Hildenberger into a precarious situation: two runners on base, nobody out, top of the Kansas City lineup coming up and the Twins, having surrendered an early four-run lead, clinging to a 6-5 lead after the Royals began the inning with three hits off Tyler Duffey and Taylor Rogers.

"When you score runs in the first five innings of the game and have your best pitcher out there, you'd like to think the game would be a little less stressful," Molitor said.

It wasn't stressful for Hildenberger, though.

"Once I saw [Whit Merrifield] wasn't bunting, I was pitching for a ground ball," Hildenberger said. "I was pitching sinkers down, down and away, changeups — anything diving below the [strike] zone. And I was able to get a ground ball."

Merrifield hit into a double play, something of a Hildenberger specialty of late. Lorenzo Cain ended the threat by flying out on a slider. And Hildenberger shut down the middle of the Royals' order in the eighth, too, using — you'll never guess — another double-play ball. In fact, three of seven batters through one stretch (over two games) grounded into two outs.

"It's been nice. The ground balls are not finding holes right now," Hildenberger said modestly. "But I think those even out at some point."

Not lately, they haven't. Hildenberger has pitched nine consecutive scoreless innings and has given up one run since Aug. 13, all while being trusted with more critical situations.

"I've enjoyed it," he said with a smile. "I've definitely enjoyed the vote of confidence."

Santana doesn't need one; even after his earliest exit in a month. His 15th victory tied him for the AL lead with Corey Kluber, Trevor Bauer and Chris Sale. And he enjoyed watching Hildenberger preserve his win.

"He came up big every time we needed him," Santana said. "He just goes about his job quietly. People don't know about him."

They know about Byron Buxton, though, who made a run-saving catch while crashing into the center field wall to end the fifth.

And they know about the Twins offense, too. Eddie Rosario slugged a 430-foot home run, hit a two-run, two-out single and drove in four runs. Eduardo Escobar had three hits, including a homer. Robbie Grossman doubled, tripled and drove in a run.

Joe Mauer doubled off Scott Alexander to drive in the final run. It gave him 861 career RBI, passing Justin Morneau for fifth on the Twins' career list.

"Joe's swing to left field off Alexander," Molitor said, "was as pretty a baseball swing as you want to see."