The packed Johannesburg City Hall broke into thunderous applause and chants of "Zuma must go" at the memorial service of struggle stalwart Ahmed Kathrada on Saturday.
This followed a rousing call by Kathrada's widow and stalwart herself, Barbara Hogan, calling on Zuma to step down.
Hogan paid tribute to her late husband, regaling the audience with anecdotes of his last days.
She then turned her attention to the recent political situation in the country, lambasting Zuma for the crisis around South African grants, the enormous nuclear deal his allies are trying to push through and the general corruption plaguing the country.
"You have sacrificed everything we stood for on the altar of corruption and greed", she said.
Former finance minister Pravin Gordhan smiled and teared up as she noted Zuma had fired "one of our finest finance ministers".
She added: "Mr President, If you have eyes to see and ears to hear, you would step down," and ended with: "Mr President, this country is not for sale."
The official memorial for Kathrada was abruptly cancelled by government in an unprecedented move for one of the last serving members of the Rivonia eight, Robben Island former prisoner and close friend to former President Nelson Mandela.
Kathrada's funeral earlier this week turned into an anti-Zuma platform with government ministers and senior ANC leaders lambasting the imminent and then widely rumoured cabinet reshuffle.
The reshuffle went ahead in the early hours of Friday morning, and saw ten minister and ten deputy ministers reshuffled. Zuma loyalist Malusi Gigaba, formerly at home affairs, replaced Gordhan.
The Kathrada Foundation organised the memorial without government, after sending out a scathing statement about the cancellation and the reshuffle.
Joburg city hall was packed to the rafters with a diverse and excited crowd spilling out through the side doors, craning to get a look in.
The streets around the hall in Johannesburg's CBD was lined with cars and crowds queued peacefully to get it.
The audience atmosphere was charged but largely positive, with some noting that the event reminded them of pre-democracy anti-apartheid rallies. The audience regularly burst into song as various speakers took to the podium.
The programme continued.