Mayo, the son of former Kaizer Chiefs striker Patrick, currently tops the scoring charts at the competition with five goals.
The 17-year-old, who plays for SuperSport United's reserve side, was rested by South Africa U-19 coach David Notoane for the 4-2 win over Fluminense at Sugar Ray Xulu Stadium on Tuesday.
Notoane wants Mayo fresh for today's semi-final against Sporting Lisbon at Moses Mabhida Stadium in Durban.
"Since I have been training and part of the team I have been itching to achieve this goal to make my mark in this tournament, which is to win the top goal scorer award. I'm currently leading the scoring charts," Mayo tells snl24.com/kickoff.
"I have been praying to God to score goals and create for the team. And everyone has been doing well throughout the two games I have been playing. So giving a contribution to the team it makes me happy and boosts my confidence to look at the semi-finals, where we will be playing against Sporting Lisbon on Thursday."
Mayo admits there is pressure to emulate his dad.
"Pressure has always been there," he adds. "Because people say I must live to my father's surname which I'm doing, and also making the name for myself, not only using the surname. I'm trying to make my name for myself which people should know that I'm Khanyiso Mayo."
Manuel Tomas, an agent from Portugal who has strong ties with super agent Jorge Mendes, has been impressed by Mayo's performance while watching the event from the stands. Mendes represents the likes of Cristiano Ronaldo, Jose Mourinho, David De Gea and Radamel Falcao.