By WILL GRAVES AP Sports Writer

PITTSBURGH  — Paul Skenes struck out seven over four-plus innings in his major league debut and Yasmani Grandal hit a go-ahead three-run homer as the Pittsburgh Pirates edged the Chicago Cubs 10-9 on Saturday.

Skenes, the top overall pick in the 2023 draft, showed flashes of why he is considered perhaps the best pitching prospect in a generation. The 21-year-old — who was greeted by a standing ovation by most of the near-capacity crowd, including girlfriend Livvy Dunne — reached 100 mph on 17 of his 84 pitches.

He was electric at times but hardly perfect. Skenes allowed at least one runner in every inning he started — including a solo homer by Nico Hoerner in the fourth — and was pulled after allowing a pair of hits leading off the fifth. He was charged with three runs on six hits with two walks and a hit batter.

“The stuff was really good, I think,” Skenes said. “Just got to get ahead of hitters a little bit, more consistently. But, I think that’ll come.”

Pittsburgh’s bullpen imploded immediately after Skenes’ exit, allowing Chicago to score seven runs to take the lead, with six coming on walks with the bases loaded, most of them on counts that weren’t even competitive.

Pirates relievers Kyle Nicolas, Josh Fleming and Colin Holderman (1-0) threw 26 balls in a span of 31 pitches sandwiched around a 2 hour, 20 minute rain delay in the top of the fifth.

The Pirates’ offense, stagnant for most of the last month, picked up the slack.

Grandal’s first home run with the Pirates — a shot to the seats above the 21-foot-high Clemente Wall in right field off Keegan Thompson (1-1) — put Pittsburgh back in front in the bottom of the fifth.

Connor Joe, Oneil Cruz, Andrew McCutchen and Michael A. Taylor also homered as Pittsburgh snapped a three-game losing streak. The Pirates’ 10 runs were a season-high. Cruz, McCutchen, Taylor and Grandal had two hits each for Pittsburgh.

“We did some really good things today offensively,” Pirates manager Derek Shelton said. “In fact I said to Connor on the way up, I forgot he hit a three-run homer, it was so long ago. But I think the fact offensively we kept grinding (was good) … very proud of our offensive group.”

David Bednar allowed Michael Tauchman’s sacrifice fly in the ninth but got Cody Bellinger to fly out to deep right field with the tying run on third to pick up his seventh save.

Miles Mastrobuoni had three hits for the Cubs. Tauchman and Seiya Suzuki added two hits apiece for Chicago.

Cubs starter Justin Steele, who had been sharp in his return from a left hamstring strain on Monday against San Diego, wasn’t quite as crisp this time around. He allowed six runs on six hits with two walks and three strikeouts in four innings.

Joe and Cruz hit back-to-back homers off Steele in the third and Taylor added a two-run shot in the fourth as Pittsburgh raced to a 6-1 lead that seemed to put Skenes in position to pick up his first victory.

That day will have to wait following a whirlwind few days.

“It’s going to be nice to get into a routine for sure,” Skenes said. “I’m big on routines and so the last week has been kind of tough with that. But, (the) bottom line is you have to go out there and pitch.”

TRAINER’S ROOM

Cubs: Placed RHP Yency Almonte on the 15-day injured list with a strained right shoulder. Chicago recalled RHP Jose Cuas from Triple-A Iowa to take Almonte’s place on the roster. … 3B Chris Morel exited after five innings with right knee soreness.

Pirates: Placed 3B Ke’Bryan Hayes to the 10-day injured list with low back inflammation and recalled INF Alika Williams from Triple-A Indianapolis. Hayes had sat out each of Pittsburgh’s last two games in hopes of a quick turnaround but the team opted to give the Gold Glove winner more time to rest.

UP NEXT

The series wraps up on Sunday. Bailey Falter (2-2, 4.34 ERA) will start for Pittsburgh. The Cubs will start Kyle Hendricks (0-3, 12.00 ERA).