And Gigi - who is dating Zayn Malik - impressed herself with her own quick reflexes when it happened.
She added: "I remember taking the time, as it all felt slo-mo, to look at him, a stranger, and my first reaction was, 'Get me out of this situation.'
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"I played volleyball, and my coaches talked about muscle memory. I started boxing two years ago and I always remembered that. Since then, I hadn't been in a situation that forced me to fight back, but it just came out when he grabbed me - it wasn't a choice. I do have that fighter in me."
And the blonde beauty can't believe people are calling it a heroic action as it was just instinct.
Speaking to Lena Dunham for Lenny Letter, she added: "It sounds cliché to say it, but in the moment, it wasn't heroic to me. It was just what I had to do. It's very touching to me that people see it that way.
"I know people are put in much worse situations every day and don't have the cameras around that provoke social-media support. I just want to use what happened to me to show that it's everyone's right, and it can be empowering, to be able to defend yourself."
- Bang! Showbiz