Former speedway world champion Michael Lee indecently touched a woman during an awards celebration, a court was told on Friday.
Ipswich Crown Court heard that she was left “utterly shocked” by the incident at the event she was attending with her boyfriend.
She alleged Lee, a former rider with the King’s Lynn Stars, said “Nice thighs”.
The alleged assault is said to have happened in November 2011 at an end-of-season speedway presentation evening at the Worlington Hall Hotel in Suffolk.
Giving evidence from behind a screen, the woman said: “I didn’t really know what to do. I was utterly shocked by it and I nervously laughed. I really regret I didn’t react differently.”
Lee, a father-of-four, was standing behind her “laughing and grinning” said the woman. Afterwards when she told her boyfriend what had happened he was “fuming”, she said.
Lee, 55, of Worlington, near Mildenhall, has pleaded not guilty to two offences of sexually assaulting the woman.
Lee later told police that what took place had been nothing more than “a friendly squeeze on the bottom”.
He has pleaded not guilty to the rape and assault causing actual bodily harm of another woman in December 2012 which he has described as “pure fabrication” with the intention of destroying him.
Earlier in the trial the jury heard claims Lee had attacked a woman in a toilet and tried to put a black bin bag over her head before committing rape.
Lee, co-promotor of the Mildenhall Fen Tigers, was crowned individual world speedway champion in 1980.
The trial continues.