PHILADELPHIA — Struggling Pittsburgh Pirates ace Paul Skenes isn’t pretending to know the answers to his sudden slipups on the mound, from where he’s dominated for two seasons.

At least he wasn’t offering any on Wednesday night after his worst outing of the year. Skenes (6-8) lasted only four innings against the Philadelphia Phillies and allowed a season-high seven earned runs in a 10-6 loss.

Since beating Colorado 3-1 on May 12 to improve to 6-2 with a 1.98 ERA, the defending NL Cy Young Award winner has not won over his last nine starts, his record falling to 6-8 and his ERA climbing to 3.62. His puzzlement is growing, too.

“I didn’t execute very well,” Skenes said. “That’s really what it comes down to. I fell behind on some counts and left some balls over the plate.”

He also took his time doing it. Skenes threw 35 pitches during a five-run Phillies second inning, highlighted by Trea Turner’s three-run homer.

“I think we’ve got a good team,” Turner said. “I think sometimes there’s no explanation, but I feel like we’ve got a good lineup and we battle. We know he’s really good, and he’s always going to give us a fight, and you kind of tip your cap when he gets you and move on, and try to have the next guy pick you up. I thought we did a good job keeping it moving against him.”

In an anticipated duel of aces and a rematch between Skenes and Philadelphia’s Zack Wheeler, played on a humid night with temperatures in the 90s, neither pitcher worked to his standard.

Skenes’ first loss in this slide came at PNC Park on May 17 at the hands of Wheeler and the Phillies, 6-0. In that game, he didn’t allow a run until the fifth inning.

On Wednesday night, the Phillies didn’t wait that long.

Pirates third baseman Nick Gonzales fielded Justin Crawford’s bases loaded grounder in the second inning and seemingly had a routine force play at the plate, but he fired the ball off runner Alec Bohm’s hand and allowed two runs to score.

Said Pirates manager Don Kelly: “The baserunner did a good job getting in the way.”

Next batter Turner hit a pitch from Skenes into the seats for his third homer in as many games to make it 5-0.

Skenes gave up a home run to Brandon Marsh in the third. And before he bowed out, he watched Bryce Harper’s liner get misjudged by Pirates left fielder Tyler Callihan for a two-run double.

It seemed Skenes’ luck was off just as much as his command.

“They’re a good lineup, but I haven’t made it easy on myself,” Skenes said. “I just have to execute a few pitches a little better, and I think it’s probably a different story.

“I don’t know … it happens. We’ll figure out what it is and we’ll just keep attacking it.”