Mr Maxwell told Liverpool Crown Court he remembered the occasion in 1992 because it was only hours before his dawn arrest by the Serious Fraud Office on charges on which he has since been acquitted.
He said he had met Mr Oyston, 62, at the Hilton Hotel in central London and had drinks in his hotel suite with the woman and the tycoon's personal assistant. The four of them had gone on to an Italian trattoria in Chelsea.
The model claims Mr Oyston raped her in 1989, when she was aged 18, at his country homenear Lancaster. He denies the charges and the rape and indecent assault of a girl aged 16.
Mr Maxwell said he had become friends with Mr Oyston, the chairman of Blackpool Football Club, after he wrote expressing condolences over their father's death in 1991.
Mr Oyston and the woman had seemed to be on "perfectly amicable" terms, Mr Maxwell said. "There was no friction at all in the room. I remember assuming she was his girlfriend."
Mr Maxwell said he had not been able to remember the woman's name but had recognised her from a photograph. Challenged about how he could remember the occasion so clearly, he said: "I have only been arrested once in my life and you don't forget it. You don't forget what you were doing a few hours before, you don't forget it ever."
A man and woman from the jury had earlier squeezed into the back seats of a Toyota Supra sports car to test the claims of the second alleged victim that Mr Oyston had forced her to perform oral sex as they were driven to his home. The case resumes on Monday.Reuse content