Eisenberg was delivering the opening monologue for "Saturday Night Live" when he was joined on stage by a member of the cast, Andy Samberg, who also portrays Zuckerberg in skits on the show.

As the two exchanged tips on their acting techniques, the real Zuckerberg was seen offstage with the show's producer begging to be allowed to go on.

"Why can't I go in there?" he said. "I'm the real Mark Zuckerberg."

"That guy's like my evil twin," he said. "Those guys are such nerds."

When Zuckerberg finally made it on stage, Samberg beat a hasty retreat declaring the encounter "awkberg."

Eisenberg asked Zuckerberg what he thought of the movie.

"It was interesting," Zuckerberg said.

(AFP)