The singer was humbled by a meeting the 71-year-old British acting icon, who provided vintage glamour at a party to celebrate 100 years of London store Selfridges.
Thrilled to be introduced to the ageing superstar, Lily, 23, let the occasion get the better of her as she leaned in for a showbiz kiss only to be rebuffed by Joanie.
Not the face: Joan Collins and Lily Allen swap hellos, but the British acting legend was not keen on a greeting kiss from the singing star
But the Dynasty legend said: '"I don't kiss people I don't know"'. However, Lily was unperturbed, and tweeted 'AMAZING!'
Aside from Joan, Lily was the evening's star attendee, and looked casually chic in a little black dress and suede green biker jacket.
Vintage glamour: Joan put on the style to attend Selfridges Big Yellow Festival opening party
She caught up with star designer Giles Deacon, chatted to Henry Holland, and enjoyed the champagne on offer as the party which was crammed with famous Brit faces.
The fashionable crowd, included bag designer Lulu Guinness, radio presenter Lisa Snowdon, and former model Jodie Kidd at the yellow themed bash, where the legendary pantone 109 sunflower shade adorned everything from balloons, to the drinks and even the waiters.
Models inc: Erin O Connor and Jodie Kidd get up close and personal
The show will be part of the MySpace Secret Show series. Fans are advised to log on to myspace.com/secretshowsuk to find out ticket and venue details – which will be revealed on the day of the gig.
The gig will have a fancy dress theme of London Tube stations, which was picked by Lily herself, and will be free to enter on a first-come, first-served basis.
Friends in high places: Joan pauses for a photo op with Mayor of London Boris Johnson
