Gwyneth Paltrow

Gwyneth Paltrow

Gwyneth Paltrow hailed Chris Martin as the "father of the year" last night.

The 'Iron Man 3' actress was host of the American Foundation for AIDS Research (AmfAR) Inspiration Gala in Los Angeles and also praised her estranged husband - who she split from in March - as she introduced a surprise performance from him and Coldplay bandmate Jonny Buckland.

And Chris - who has children Apple, 10, and Moses, eight, with Gwyneth - joked he was actually Justin Bieber in disguise.

He 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."

'SexyBack' singer Timberlake was actually seated with Gwyneth at the gala, along with Rihanna, Rita Wilson and the evening's honouree Tom Ford, and kicked off the auction when he bid $80,000 for a Damien Hirst painting.

Miley Cyrus splurged $300,000 on a print of a naked woman after getting into a bidding war with Rihanna and Tom, and the trio later donated another $200,000.

Miley then said on stage: "I'm a little drunk. That's why I'm a half a million deep."

Her admission prompted Gwyneth, 42, to later bemoan her own financial situation.

She joked: "I'm drunk now so this isn't fair. And Miley Cyrus has so much more money than I do. What the f**k?"