Kate Hudson left onscreen rival Anne Hathaway nursing a bruised head when a fight scene in new movie BRIDE WARS went wrong.
The pair play pals who fall out when they both plan to marry on the same day.
The actresses both insist rumours of an onset bust-up are untrue - but they admit one slapping scene took a real twist and left Hathaway cradling an ice-pack.
Hathaway tells People magazine, "Did you notice Kate's enormous wedding ring in the movie? Imagine, surrounded in a cloud of tulle, Kate Hudson's hand with the 9.000 carat diamond coming out and smacking you across the face and staying in character."
Red-faced Hudson adds, "It was not intentional. I hit her and I went, 'Oh God', and she's like, 'No, I'm fine, keep going.'
"And then I saw Annie sitting in a chair with an ice pack!"