The country's Premier Soccer League (PSL) said it had sold 80,000 seats for the one-day tournament, which features four teams in three separate matches, and handed out a further 7,000 complimentary tickets.
It was the first event at the stadium since Spain beat the Netherlands 1-0 on July 11 to lift the World Cup.
A 88,791-seat sellout for the Tri-Nations test between the Springboks and New Zealand's All Blacks on August 21 has already been announced.
"We certainly want to see the fans coming into the stadiums, we want to see all the people who were at the World Cup coming back and experiencing more," said the league's chief executive officer Kjetil Siem.
The stadium's capacity has been reduced to 52,000 with the removal of temporary seating installed for the World Cup. PSL spokesman Altaaf Kazi told Reuters they were confident of a sell-out crowd.
Saturday's Charity Cup traditionally opens the season with the country's four most popular clubs, voted for by public ballot, contesting two semi-finals and then a final, starting at 10 am local time and concluding well into the night.
