Duffy accepted her first of three Brit Awards - for best British female - saying it was "lucky her mum didn't have a son".
Take That missed out on best British group at the ceremony at Earls Court, but thrilled with their live performance.
The Pet Shop Boys received the outstanding contribution award, and closed the show with a medley of their hits.
British breakthrough nominees The Ting Tings joined forces with best female contender Estelle for a performance.
Kylie Minogue's back up dancers looked suspiciously like co-hosts James Corden and Matt Horne.
Katy Perry admitted she was feeling "sick" as she accepted her award for best international female.
Girls Aloud celebrated their first ever Brit as Sarah Harding told the audience that it was "about time" they won.
TV host Alan Carr spotted a lookalike among the fans gathered outside Earls Court.
Singer and former Strictly Come Dancing champion Alesha Dixon was one of the first to arrive at the annual ceremony.
U2 opened the show with their new single Get On Your Boots.
Elbow added best British band to the Mercury Prize they picked up for their record The Seldom Seen Kid last year.