Olivia Wilde: Chris Hemsworth and I Competed Over Our Hair!

When Olivia Wilde took on the role of 1970s supermodel Suzie Miller for the upcoming film Rush, she had to lighten her hair and get a retro shag cut.

And apparently her gorgeous makeover sparked some on-set jealousy from co-star Chris Hemsworth, who plays Formula One racer James Hunt in the Ron Howard directed flick.

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"We competed over haircut and hair color, but I think he won," the 28-year-old actress told Us Weekly at the Tribeca Film Festival premiere of Deadfall in New York City Sunday. "He has an amazing head of hair!"

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This is the second major hair change Wilde has made this year. In January she transformed her style from long and brown to highlighted and shoulder-length.

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Last month fans got a look at Wilde and Hemsworth engaging in a passionate kiss while filming a wedding scene for the movie, but in real life she's dating SNL funnyman Jason Sudeikis.

Olivia Wilde and Chris Hemsworth on the film set of 'Rush' on April 2, 2012 in London, England.
Credit: SAV/FilmMagic