'Harry Potter and the Deathly Hallows - Part 1' UK Premiere

Emma Watson's spell is over as she swaps pretty vintage dress for trousers and flats at Harry Potter premiere afterparty

She looked stunning as she graced the red carpet at the premiere of Harry Potter And The Deathly Hallows: Part 1 last night.

But, just hours after wowing fans in a pretty vintage feathered Rafael Lopez for Atelier Mayer dress, Emma Watson changed into a less-than-exciting ensemble of black trousers, a grey mac and flat shoes for the film's official afterparty.

The outfit was a far cry from Emma's earlier ensemble, and was more akin to the casual clothes the 20-year-old actress wears when she is on campus at America's Browns University.

Casual nighttime look: Emma Watson opted for a grey mac, black trousers and flat black shoes at the afterparty of the Harry Potter premiere

What a difference: Emma's casual outfit was a far cry from the glamorous vintage dress she wore earlier on the red carpet

And, combined with Emma's new elfin hairstyle, the entire ensemble resulted in Emma looking a lot younger than her 20 years.

But Emma said recently while her fans may have been shocked by the drastic change to her image when she swapped her long locks for a face-framing crop, she loves her new hair.

She said recently: 'It was really fun, actually, having it cut. It was really fun… Sometimes I still forget that I don’t have it anymore.'

And Emma, who plays Hermione Granger in the films, said she had decided to cut her hair when her obligations with Harry Potter had finished.

Co-stars: Earlier in the evening Emma posed with co-stars Daniel Radcliffe and Rupert Grint on the red carpet

Matching: Emma also posed with Harry Potter author JK Rowling, who wore an incredibly similar outfit

She told Vogue magazine recently: 'All the normal things girls do, I couldn't [because of Harry Potter. For the nine years I was on Harry Potter I was contractually obliged not to cut my hair, not to tan.

'When I got the chance to change my appearance, my hair is what I did. I didn't realise until afterwards how significant it was because, of course, the hair was Hermione's defining feature.

Earlier in the evening, Emma was joined on the red carpet in London's Leicester Square by Harry Potter co-stars Daniel Radcliffe and Rupert Grint.

Harry Potter And The Deathly Hallows has been split into two films because producers felt there was too much material to fit in one movie.

Part 1 sends Harry and pals Hermione (Watson) and Ron (Rupert Grint) outside their usual haunts at Hogwarts School of Witchcraft and Wizardry as they search for artefacts that are the key to the power of dark Lord Voldemort (Ralph Fiennes).