Simon Cowell's ex-girlfriend "lunged" at the 200lb woman who tried to choke her.

Terri Seymour was assaulted outside Los Angeles' Nokia Theatre - where Simon's TV show 'American Idol' was being filmed in front of a star-studded audience, including Katie Holmes and her daughter Suri and actor Sir Anthony Hopkins - on Tuesday (19.05.09).

According to police, Janice Thibodeaux, 33, approached Terri and asked her if she was still dating Simon - who she split from last November after a six-year relationship - before attempting to choke her.

Terri said: "It was all so sudden - very scary. Nothing like this has ever happened to me before.

"She came over to me and said, 'You're that girl from TV, right?' And I said, 'Yeah.' The next thing I know, this woman had me in a headlock and tried to choke me."

After a few seconds, Terri's initial shock wore off and she bravely fought back.

She explained to US TV show 'Extra': "I yelled out, 'What are you doing?' and I lunged at her. She let go and took off running."

A source added: "It was scary just how close the woman got to Terri, she just flipped out."

Nearby police officers gave chase to Thibodeaux and managed to stop her. She has been charged with felony battery and is currently being held on $52,700 bail.

Terri said: "The police were fantastic. They were close by and managed to catch her."

After the frightening incident, the TV entertainment reporter was escorted home by police but did not need any medical attention.