Australian heart-throb Heath Ledger was left red-faced during a fight scene in CASANOVA, after his trousers split.

The actor, who has been nominated for Best Actor In A Drama at next year's (06) Golden Globes, learned to sword-fight for the period comedy, but found his tight trousers restricting during the physical scenes.

His co-star SIENNA MILLER says, "I was not the most naturally gifted sword fighter, but I learned.

"Heath was a very patient partner. He split his trousers on a lunge, which made me laugh and that broke the ice from day one."