Van Wyk, who clinched the final spot in the 32-man field in a play-off, derailed Dylan Naidoo’s hopes of a double in the prestigious junior championship when he downed the newly-crowned Stroke Play champion 3 & 2.
Sinclair served up the second big blow in the first round when he dispatched the country’s current number one ranked amateur Tristen Strydom 5 & 4.
The Centurion player kept his winning run going with another 3 & 2 result against Sentanio Minnie from Ekurhuleni in the second round, but
Van Wyk bowed out to Gauteng North’s JP Cooper, who clinched a 1-up victory at the 18th hole.
The other six players who advanced to the quarter-finals are Slade Pickering from North West, Kyle Barker from Central Gauteng, Luca Filippi and Matt Saulez from KwaZulu-Natal, Southern Cape’s Jovan Rebula and Estiaan
Conradie from Gauteng North, who booked his spot in the final eight with victory at the 19th hole against Deon Germishuys from Western Province.