LONDON — An alarming onstage tumble by a heavily pregnant Gillian Anderson at the world premiere of “How to Lose Friends & Alienate People” did not dampen the excitable mood at the Empire, Leicester Square on Wednesday.

Eight-month pregnant Anderson, who stars as a conniving publicist in the pic, toppled over while pretending to punch wise-cracking director Robert Weide who, previous to introducing her onstage, joked “wouldn’t it be great publicity if her water broke onstage.” Playfight went a bit wrong when the pair both fell over but Anderson was soon up on her feet, albeit looking pretty flustered.

Brit comic Simon Pegg, who toplines as a cocky Limey hack struggling to adapt to the bitchy environment of a slick New York-based glossy mag, delighted his home town crowd by partying hard at the Shoreditch House after-party.

Also on hand were, producers Steve Woolley and Liz Karlsen and guests Andy Serkis, Martin Freeman and Nick Frost.