In a mansion-sized tent at the Hotel du Cap-Eden Roc outside Cannes, Tom Ford and Eva Longoria were trying to sell a collection of dresses to the highest bidder. The garments up for grabs at the Thursday night’s amfAR Cinema Against AIDS auction had just been showcased in a fashion show on steroids, which featured 40 models strutting up and down the runway and then returning onstage for an impromptu dance. The crowd of A-list celebrities, oligarchs and other rich-and-famous were impressed.

But nobody seemed to love the spectacle more than “Blurred Lines” singer Robin Thicke, 38, who sat a table close to the action. He kept standing up, sitting down, standing up and clapping, like he was cheering on his favorite sports team. His date, 20-year-old April Love Geary (also a model), didn’t seem to mind.

This annual amfAR event feels like the Golden Globes (or the Met Gala) of France. And these dresses — from Prada, Celine, Gucci, Louis Vuitton and practically every other designer you can name at Barneys — were a hot item. As art auctioneer Simon de Pury (a more aggressively Swiss version of Bob Barker) tried to run the bids up, supermodel Karlie Kloss stuck both arms in the air, in a levitating pose. A friend shoved her onstage. “Bitch,” Kloss whispered, before she took the microphone and begged the crowd for more money. In addition to the dresses, she’d offer an intimate dinner with one of the models, and a picture posted on all 40 of their Instagram accounts.

These added bonuses didn’t result in any more bids, but the dresses still sold for $900,000. In total, the amfAR event on Thursday night was able to generate $30 million for AIDs/HIV research, on top of the $140 million that Cinema Against AIDS has raised over 22 years.

This year’s guest list included Leonardo DiCaprio, who wore a ponytail and smoked an e-cigarette while sipping on a glass of white wine; Jake Gyllenhaal; Marion Cotillard; Michael Fassbender; Sienna Miller; Chris Tucker; Michelle Rodriguez; Harvey Weinstein; Kendall Jenner; Isabella Rossellini; Kenneth Cole; Xavier Dolan (in a floral-print jacket); and Paris Hilton, who had come to the South of France to DJ and catch Pixar’s out-of-competition premiere of “Inside Out.” (“It’s an amazing film,” Hilton glowed).

Like everything related to money and Hollywood, the patrons only opened their wallets following an elaborate show. Andrea Bocelli performed two songs, and invited the audience to “sing along” with him. Mary J. Blige belted out her trademark tune “Family Affair” that had the audience on their feet.

Among the big purchases: “Coloring Book,” an 18.5-foot sculpture by Jeff Koons ($13 million); a statue by Colombian artist Fernando Botero ($2.2 million); a Banksy portrait of a police officer with a yellow smiley face that came from DiCaprio’s personal collection ($1 million); and Longoria shelled out $600,000 for an Andy Warhol portrait of amfAR’s grande dame Elizabeth Taylor.

DiCaprio also offered a package that included a night out on a yacht with him that sold for $280,000, while a home-cooked meal with 11 of your friends at Boccelli’s house went to two bidders at $1 million each. DiCaprio never took the stage, as he remained at his table with Duchess of York Sarah Ferguson. Fassbender made the rounds, greeting friends. After ogling the models, Thicke disappeared into a bathroom stall, and the men’s room was suddenly overflowing with women in fancy ball gowns who didn’t want to — or actually couldn’t — wait in the longer line next door.

Charli XCX opened the show, and the band Imagine Dragons closed out the night, but not before a drunk woman climbed onstage during the set. She grabbed the microphone and urged everybody to clap louder. But by then, the tent had started to clear as the crowd headed to the outdoor after-party, where Rodriguez would DJ until the early hours of Friday morning.