04/19/2012 10:15 am ET Updated Apr 19, 2012

'Five-Year Engagement' Premiere: Stars Party At Tribeca Film Festival's Opening Night

The Tribeca Film Festival kicked off its 11th annual edition with the world premiere of Nicholas Stoller's "The Five-Year Engagement" at the Ziegfeld Theatre in midtown Manhattan on Wednesday night. Stars Jason Segel, Emily Blunt, Alison Brie, Dakota Johnson and Kevin Hart joined Stoller, producer Judd Apatow and assorted A-listers from Robert De Niro to Julia Louis-Dreyfus for the screening and a wedding-themed post-party at the nearby Museum of Modern Art.

Stoller, who reunited with co-writer and star Segel after directing him in "Forgetting Sarah Marshall," began the evening with a joke from "the old country" -- "Marriage is a three-ring circus: engagement ring, wedding ring, suffering" -- and then introduced the actors with whom the audience would be spending "the next six hours."

He was almost half serious, it turned out, as the unconventional romantic comedy unspooled over the better part of two hours. But the home-team audience stayed engaged throughout, laughing along to the ups and often brutally painful downs experienced by Segel and Blunt, who play a loving couple whose wedding gets serially postponed owing to a succession of increasingly unpleasant circumstances.

Afterward, the well-dressed throng walked the two long blocks to MoMA, where the lobby and the Donald B. and Catherine C. Marron Atrium had been transformed into a faux-wedding, complete with his-and-hers buffet offerings and dessert displays studded with candy-colored petit fours. (The wait staff wore pinks ties, which not only completed the wedding theme, but also recalled the cult television series "Party Down.")

VIPs were ushered into a cordoned-off area on the ground floor and seated at tables reserved for ROSENTHAL (festival co-founder Jane Rosenthal) and DE NIRO (obvious; the Oscar-winner munched salad and chatted with table mate Cuba Gooding Jr.). Others observed making the pseudo-post-nuptial rounds: Michelle Williams (whose relationship with Segel is the talk of the celebrity blogosphere), Elizabeth Banks, Leelee Sobieski, Bill Hader, Judd Apatow and Beau Bridges, who exchanged a hearty bro-hug with De Niro.

"The Five-Year Engagement" hits theaters on April 27, one day before the Tribeca Film Festival closes for the year. Check out Huffington Post's full coverage of the 11th annual fest by clicking here.

PHOTOS: "Five-Year Engagement" Premiere

'Five-Year Engagement' Premiere