Michelle Williams oozes style on the yellow carpet at London Oz premiere... but Mila Kunis swamps herself in large rag like gown

PUBLISHED: 13:18 EST, 28 February 2013 | UPDATED: 13:26 EST, 28 February 2013

They've so far been head-to-head in the style war as they launch their promotional storm of new movie, Oz: The Great And Powerful.

But it was Michelle Williams who came out shining on Thursday night as they premiered the movie in London.

The Brokeback Mountain star dazzled in her emerald frock as she walked the 'Yellow Brick Road' in place of the usual red carpet.

Emerald Queen: Michelle Williams wins in the fashion stakes as she shows up to the London premiere of movie Oz: The Great And Powerful on Thursday evening

Style war: Michelle Williams stunned in her strapless aqua frock while Mila stepped out in the rag like gown for the screening

But while she oozed style in her strapless gown her fellow star Mila Kunis had an unusual fashion faux pas as she managed to swamp her tiny figure in a large dress

They've got plenty of designer couture on hand for their red carpet premieres of Oz: The Great And Powerful.

But when it comes to their own personal style, Mila Kunis and her co-star Michelle Williams could not look more different.

The actresses were spotted showing off their opposing casual dress as they arrived in London on Thursday after flying in from Russia.

Chic: Michelle Williams arrives at London hotel Claridge's in beige trenchcoat, skinny jeans and kitty ballet pumps

Dressed down: Mila Kunis was more relaxed of the pair and wore a leather panelled jacket, skinny blue jeans and trainers

Michelle, 32, was the chicer of the two in a beige trenchcoat and skinny black jeans .

She gave a quirky twist to her ensemble with a £465 pair of Charlotte Olympia 'Kitty' velvet slippers.

Meanwhile, Mila, 29, went for a more comfortable look in a black T-shirt, scarf, leather panelled jacket, skinny jeans and high-top trainers,

Keeping her head down: Michelle's promotional tour comes amidst reports she has split from Jason Segel

Their arrival in the British capital ahead of Thursday night's UK premiere came after the Moscow screening the previous night.

Mila looked stunning in a form-fitting purple Atelier Versace gown, which hugged her trim figure in all the right places.

Meanwhile, Michelle went for a glitzy gold, bronze and black Jason Wu number as she joined her co-stars Mila and James Franco on the red carpet.

Star style: Mila kept her eyes shielded from the paparazzi's flashes with a pair of Ray Ban sunglasses

All three actors are expected to join director Sam Raimi and co-star Rachel Weisz at the premiere at the Empire Cinema in Leicester Square on Thursday evening.

The Oz promotional tour comes as it emerged this week that Michelle has quietly ended her one year relationship with actor Jason Segel.

Apparently it was the couple's long-distance relationship - she lives in Brooklyn, New York, while he is based in Los Angeles - which was the main factor behind the split.

Oz: The Great And Powerful is due for release in the UK and the USA on March 8.

Glamour: Mila (left) wore a slinky Versace gown at Wednesday's Moscow premiere, while Michelle opted for Jason Wu