During office hours he’s Guillaume Retief, a 25-year-old doing his articles to become an accountant.
But after a day of poring over figures he shuts the door on the corporate world, swops his tie for boxing gloves and drops his polite office manner to assume a surprisingly intimidating demeanour.
Guillaume has joined a sport trend that has recently become popular in South Africa: white-collar boxing.
An increasing number of careerminded people building the economy by day are whacking the day-lights out of one another at night.
Read more about this in the next issue of YOU.
Follow YOU on Twitter.