new york

If it seemed like Twentieth Century Fox’s “X-Men: First Class” premiere at the Ziegfeld was a spur of the moment affair, that’s because it was.

Fox’s Tom Rothman said the May 25 event was planned in just 24 hours.

Indeed, an odd combo of go-go dancers, 1960s cars and the same quartet that performed at last month’s “Water for Elephants” preem adorned the black carpet.

“It started off as a little screening,” Rothman said. “But to tell you the truth, it came out of a lot of the press response from the early screenings and their enjoyment of the movie’s 1960s vibe.”

Pic’s James McAvoy, who posed alongside co-stars Kevin Bacon and January Jones, seemed amused.

“Was I surprised that they decided to spend two bucks and fifty cents on a premiere and then at the last minute decided to change that? Yeah, kind of,” said the star. “I think at the last minute they felt so proud of the movie that they said, ‘You know what? We have got to do something a little more.’ So more power to them for getting this together in 20 seconds.”