NEW YORK — If this is who David Peterson is, the Mets have far less reason to worry about their rotation this summer.

Peterson matched his career high with 10 strikeouts in a 5-1 win over the Phillies on Wednesday, pumping his fastball regularly into the mid-90s and showcasing perhaps the most devilish slider of his young career. The left-hander fanned six batters over the first three innings at Citi Field and didn’t relent much from there, allowing his only run on a Jean Segura homer in the fifth.

By that time, Peterson was already leading thanks to an RBI single from Dominic Smith and a run-scoring double play by Pete Alonso. Brandon Nimmo led the Mets’ offensive charge with a three-hit game, Alonso added a late sacrifice fly to give them some breathing room and James McCann added a two-run homer — his first as a Met.

After Peterson departed, relievers Jeurys Familia, Aaron Loup and Edwin Díaz combined on the final nine outs to seal the victory.