Actor Amber Heard broke down in tears on the witness stand on Thursday while testifying in the defamation trial against ex-husband Johnny Depp claiming that he had sexually assaulted her with a liquor bottle during a fight in Australia, shortly after the pair got married.

Recounting the ordeal, the "Aquaman" actress said that the fight in Australia -- during filming of the fifth "Pirates of the Caribbean" film in March 2015 -- was prompted by Depp's jealousy and her concern about his drug use.

She said Depp had repeatedly hit her, threw bottles at her and choked her against a refrigerator, before finally getting her on top of a countertop and penetrating her with a bottle.

"I remember just not wanting to move," she said. She said she remembered thinking, "Please, God, I hope it's not broken."

Heard is defending herself in a $50 million defamation trial in Fairfax, Virginia. Depp has sued his ex-wife Heard for writing an op-ed piece for the Washington Post in which she claimed that she was a victim of domestic abuse.

Depp has denied ever assaulting Heard. He already told the jury his own version of events surrounding the Australia fight, alleging that she severed his fingertip when she threw a bottle at him.

Heard has previously testified about these incidents during a trial in the United Kingdom, but the details of the alleged sexual assault were kept confidential in that proceeding.