Gwyneth Paltrow Introduces Chris Martin's Surprise Performance, Miley Cyrus Drops $500,000 at AmfAR Gala

Gwyneth Paltrow and Chris Martin continue to prove they're the friendliest exes ever.

The Oscar winner not only hosted last night's American Foundation for AIDS Research (AmfAR) Inspiration Gala in Los Angeles, but she started the evening off by introducing a surprise performance by Martin and his Coldplay band mate Jonny Buckland.

Paltrow gushed to the crowd that Martin is the "father of the year."

As Martin walked onto the stage, he pointed to Buckland and said, "This is Justin Timberlake. I'm Justin Bieber. We are 'Bieber and Timberlake' and we play Coldplay covers just for the money...So you're very privileged to be here to watch us do this because normally we play Bieber and Timberlake songs."

Timberlake was actually at the gala, sitting at table with Paltrow, Rihanna, Rita Wilson and the night's honoree, designer Tom Ford.

J.T. helped start the live auction off when he won a Damien Hirst painting for $80,000 followed by Rihanna taking home a pair of diamond Harry Winston earrings for $35,000. Miley Cyrus dropped a whopping $300,000 on a print of a naked woman by photographer Ryan McGinley after getting into bidding war with Rihanna and Ford.

Later, Cyrus, Rihanna and Ford donated another $200,000 each to the AIDS group.

"I'm a little drunk. That's why I'm a half a million deep," Cyrus said from the stage before talking about her new role as MAC Cosmetics' new Viva Glam celebrity spokesperson.

"If I'm going to have a voice I would like to start an open dialogue about prevention and awareness and how people in the world have been effected by HIV and AIDS," Cyrus said. "Hopefully, I could break down people's walls that have been built up around sexuality. I'm obviously not too embarrassed to talk about these things, especially with young people."

Paltrow then returned to the stage to introduce Rihanna, who presented Ford with his award (I'll have more on that later).

"I'm drunk now so this isn't fair," Paltrow cracked. "And Miley Cyrus has so much more money than I do. What the f--k?"

The night ended with another surprise performance by Diana Ross.

Produced by Josh Wood Productions, the benefit's other celeb presenters and guests included Sharon Stone, Eddie Redmayne, Lea Michele and her boyfriend Matthew Paetz, newlyweds Matthew Morrison and Renee Puente, Evan Ross and wife Ashlee Simpson, Tracee Ellis Ross, Jesse Metcalfe, Cara Santana, January Jones, Kristin Davis, Molly Sims, Milla Jovovich, Michelle Rodriguez and Gilles Marin