Bairstow, 23, convincingly came through an all-English semi-final against John Gough by 5&4 to seal his place in the 36-hole showdown, while teenager Potgieter, 17, edged out Irishman Alex Maguire 3&1.
As well as winning one of the most prestigious titles in the amateur game, the victor tomorrow can look forward to competing in The 150th Open at St Andrews next month, the 2023 US Open and, by tradition, an invitation to play in the Masters Tournament.