Pregnant actress Gillian Anderson jokingly threw a punch at her director at a London film premiere and ended up on the floor, People.com said.

The incident took place Wednesday night at the debut of How to Lose Friends and Alienate People, in which Anderson stars alongside Kirsten Dunst, Megan Fox and Simon Pegg.

While introducing the movie, director Robert Weide quipped that it would be great publicity if Anderson went into labor during the premiere.

The actress, who is pregnant with her third child, responded by pretending to slug the director, losing her balance and hitting the floor in the process, People.com said.

Weide quickly reassured the audience Anderson was not injured in the fall and joked, Is there a lawyer in the house?

Anderson is best known for her roles in the X-Files TV show and films. (c) UPI