Winnie Madikizela-Mandela was expected to accept the ANC centenary torch at her home in Orlando West, Soweto, on Saturday morning.
The torch arrived in Gauteng on June 1 after being received by former President Nelson Mandela at his home in Qunu in the Eastern Cape.
After its month in Gauteng, the torch would be sent to Limpopo to continue its journey, which started in Mangaung, in the Free State, in January.
Journalists arrived early at Madikizela-Mandela's home, where preparations for the celebration were underway under the trees in her garden.
A vehicle in the driveway played slogan songs of the ANC, creating a carnival atmosphere. - Sapa