Renee Zellweger and Bradley Cooper had an uncomfortable run-in at the annual Constume Institute gala Monday night at the Metropolitan Museum of Art.

The couple who broke up in March after two years, came within feet of each other at the star-packed gala. A witness told us: “They stared for a quick second, surprised and straight in the face and turned away. It was an awkward moment, and they split in separate directions.”

Madonna arrived alone at the gala — where Florence and the Machine performed for the Anna Wintour-handpicked crowd — leaving latest boy toy Brahim Zaibat behind for the company of Lorenzo Martone and photographer Steven Klein.

Later at the official Vogue/Stella McCartney after-party at new restaurant Crown, The Material Girl held court in a private room with Rihanna, Marc Jacobs, Paul McCartney and girlfriend Nancy Shevell. DJ Cassidy spun an after-hours set that got the former Beatle dancing to various Michael Jackson tunes.

Also at the Crown, Beyoncé and Jay-Z — earlier booed on the red carpet at the Met when they didn’t stop for interviews — hung out in a booth with Lyor Cohen and Tory Burch. “Glee” buddies Matthew Morrison and Gwyneth Paltrow were spotted having an intimate chat during which Paltrow’s hand rested on Morrison’s chest. Billy Joel’s ex Katie Lee was held up at the door of the bash, and was seen arguing with staff.

Lee then headed to the Top of The Standard hotel, where new couple Amar’e Stoudemire and Ciara hung close while a well-heeled crowd — including Salma Hayek, Kanye West, Swizz Beatz and Alicia Keys — partied until 4 am. When a guest asked Mickey Rourke if he was wearing McQueen — who was honored that night — he replied: “I’m not quite skinny enough to wear McQueen.”

Rourke was later spotted holding up a wobbly Jason Statham as the “Transporter” star looked for his girlfriend, Rosie Huntington-Whiteley, who was upset when she lost an earring, sending Statham and Rourke crawling around the floor to find it.