KANSAS CITY — For a little over four innings, Royals right-hander Jakob Junis thought he had it all working.

The Royals were hanging on to a one-run lead over the Phillies on Sunday at Kauffman Stadium, and Junis was cruising. But that all changed with an error, three Junis walks and two big two-run hits off reliever Richard Lovelady as the Phillies erupted for a six-run fifth inning on their way to a 6-1 victory and a series win.

Junis had given up just two hits through four innings and got an easy out to start the fifth. Then a seemingly harmless grounder by Phillies left fielder Nick Williams to shortstop Adalberto Mondesi turned everything south.

Mondesi, who had made just two errors all season, charged the slow roller and fielded it cleanly. But as he began to throw, he bobbled the ball for an error. For whatever reason, that foible opened the floodgates.

The next four Philadelphia batters: walk, RBI single, walk, RBI walk. And that was it for Junis.

“You make the play and then sometimes you hurry the transfer,” Royals manager Ned Yost said of Mondesi’s error. “He hurried the transfer. He just lost it.”

Mondesi, though, has been spectacular defensively at times this season.

“Unbelievably good,” Yost said. “Lights out. Pop-your-eyes-out good. Makes plays like the other night when he’s almost to third base and then throws back and gets a guy out. He’s been really good.”

After the error, Yost had one thought about Junis.

“Cover the fielder,” Yost said. “Cover [the error]. It wasn’t from lack of effort [from Junis]. He just lost his command a little.”

Junis, who said his four-seam fastball had as much life as at any time this season, began missing the corners he had owned through four innings.

“I got away from my command a little bit,” Junis said. “My fastball started missing a little bit. I fell behind in the count when I really needed to get ahead in the count.”

The error didn’t bother him, Junis said.

“There was one out and we made an error,” Junis said. “You can live with that and work around that. But I didn’t make good enough pitches.”

“He was just missing,” Yost said. “It wasn’t like he was crazy wild. His command just got a little off. They’re a pretty good offensive team, an experienced offensive team, and they have a pretty good idea of the strike zone and they just weren’t biting.”

Still, the Royals trailed only 2-1 when Lovelady entered to face J.T. Realmuto with the bases loaded. Realmuto smacked the first pitch for a double, scoring two.

“First pitch came in trying to get ahead in the count and it was up in the zone,” Yost said.

Odubel Herrera then whacked a slider for a two-run single, and the game was pretty much out of reach, especially the way Phillies starter Cole Irvin was dealing in his Major League debut. Irvin went seven innings and gave up five hits and one run while striking out five.

“He attacked us and hit his spots,” Royals left fielder Alex Gordon — who drove in the team’s only run of the afternoon — said. “We didn’t do too much.

“We had his Minor League video so we kind of knew what to expect. We thought he’d nibble more than he did. He came right at us.”