Dylan McDermott flexed his muscles for new girlfriend Maggie Q over the weekend.

With nearly two decades on her, McDermott, 53, brought Maggie, 35, to a workout class at Barry’s Bootcamp in Chelsea, where he’s a regular. It was the actress’ first time at the fitness studio.

Not that the former “Nikita” star, who’s done her fair share of on-screen butt-kicking, couldn’t keep up. A source in the class tells Page Six the shapely stunner “was holding her own both during the running and weight lifting portions of the class.”

“Impressive for her first time,” the witness added.

The “Stalker” co-stars were first romantically linked at the end of October.