Close encounters of the Thom Browne kind went down a treat on Monday evening as the American designer let an extraterrestrial theme invade his usually dead-serious, tailored universe of gray flannel, seersucker, tweed and repp stripes.

Little green men — only they were not so little, stood on tall, lace-up platform boots — minced through the Left Bank mansion Karl Lagerfeld once called home, their blazers and pants sprouting extra sleeves and pant legs.

Normally this kind of radical design gesture is better left to the likes of Rei Kawakubo, but Browne won over the crowd with the humor — and staggering workmanship — on display.

“Toy Story” aliens and Minions oohed and ahed over an operatic soundtrack, and a troupe of silver-faced men in gray flannel suits consecrated the space, handing out cards to select guests that read: “We come in peace.”

Immediately you could spy a link between the stereotypical ’50s portrayal of aliens — green skin and outsized eyes — and the crossed tennis racket embroideries Browne applied to his ladylike tweed ensembles in yellow and pink.

“The construction of everything is very serious, but I wanted to make sure that it had a very light-hearted kind of feel to it,” the designer said when asked about the UFO-related them.

The American designer zhuzhed up a bevy of pleated skirts with imagination and intense craftsmanship, incorporating zippers, repp neckties, beaded embroideries or raw edges, giving each a distinct personality. There were also many handsome coats, with frothier-than-usual fabrics and embellishments.

He reprised anatomical embroideries from his fall 2024 couture show, here on sheer, body-hugging tops, and used sterling sliver grommets to decorate several of his layered-up ensembles. Why?

“I do love the idea of mixing couture details and elements into my ready-to-wear collections,” he said.

The finale music prompted another chuckle: The Carpenters’ oddball 1977 hit “Calling Occupants of Interplanetary Craft.”

Most extraordinary craft, indeed.