(CNN)Imagine "Saturday Night Fever's" Tony Manero with some dad moves.
John Travolta shot to superstar status as that disco-dancing character in the 1977 film, and four decades later he's still grooving.
The actor jumped on stage with 50 Cent as the rapper performed "Just a Lil Bit" at the Cannes Film Festival.
Naturally the moment went viral after 50 Cent shared a video Tuesday.
"Me and John Travolta partying," the rapper tweeted. "l swear l only came out here because of him."
The impromptu performance happened at a party following the premiere of Travolta's film "Gotti," which he was promoting at the international film festival in southern France.
The actor stars as mobster John Gotti and his real-life wife, Kelly Preston, plays Gotti's wife Victoria.
Travolta, 64, is no stranger to Cannes. This year, he's also celebrating the 40th anniversary of "Grease," another movie where he busts a move, and picked up the inaugural Variety Cinema Icon Award.
The star told USA Today of his performance with Fiddy, "It was my idea to go up and do it. I couldn't leave him hanging."
"I thought, 'I'm going to go and make something viral here," he said. "If (50 Cent) is going to travel 20 hours to get here, the least I can do is go up and hang with him on stage."
In the brief video Travolta, wearing a tux, dusts off some head shakes, hand claps and other gentle moves.
"The dance was just whatever I felt at the moment, it doesn't really have a name to it," he added. "It's just being cool, I guess."
Travolta also explained that rapper Pitbull, who wrote the score for "Gotti," was originally set to perform at the after party, but he got sick and 50 Cent stepped in at the last moment.