The juror was discharged after he admitted his bias - Mackem is slang for a Sunderland resident - the day after last Sunday's Tyne-Wear derby.
A new jury was empanelled and the trial continued, with the defendant, David Blake, being found guilty of rape.
The 44-year-old of North Farm Avenue, Sunderland will be sentenced on 13 May.
The trial started at Newcastle Crown Court on Monday, the day after Sunderland beat their North East rivals 3-0 in a Premier League match at St James' Park.
The case's restart meant the prosecution's opening had to be repeated for the new jury, so the victim had to watch her video evidence being played twice.
Blake had denied raping the woman who had fallen asleep in a spare bed, alone, after a party at a flat.
But he was found guilty at the end of the four-day hearing, and warned by the judge he faces a jail term when he returns to the court for sentencing.