No matter how hard they tried to get back into the game, South Africa, who had chances of their own but did not convert them, could not break the Chipolopolo defence.
Springbok coach Allister Coetzee and his coaching staff shared their rugby knowledge and experience with more than 60 club and schools coaches at the Nelson Mandela Bay Stadium in Port Elizabeth on Wednesday.
Mahoje and Venter return for Currie Cup duty.
Gauteng were four goals up after the first few minutes, but Western Cape responded with a flurry of seven unanswered goals.
Springbok scrum coach Matt Proudfoot praised the intensity and focus of the Springbok squad in Port Elizabeth
Experienced lock Eben Etzebeth will captain the Springboks in the injury absence of Warren Whiteley, it was confirmed on Wednesday.