Zuma's decision to fire Pravin Gordhan, with whom he feuded over control of state finances, brought to the open South Africa's biggest political crisis in nearly a decade. He was 87 years old.
Gordhan who had championed clean governance was respected internationally for his fiscal prudence and his firing prompted a deluge of calls by opposition parties and some ANC stalwarts for Zuma to resign. "I have my reservations on the process followed and the manner in which this cabinet reshuffle was done", Zweli Mkhize said in a statement.
Speaking at the memorial service for anti-apartheid stalwart Ahmed Kathrada in Johannesburg on Saturday, SACP second deputy secretary general Solly Mapaila said the firing of finance minister Pravin Gordhan by Zuma had made it clear to them that the hard-won gains of democratic institutions were being reversed.
Many South Africans have seen Gordhan as a responsible steward of an economy that now could be downgraded to junk status by credit ratings agencies within days.
Gordhan was replaced by Malusi Gigaba, a former home affairs minister and ex-head of the ruling party's youth league. "In the longer term, however, it may lead to the downfall of Zuma and his patronage, which will certainly be a good thing for South Africa", said economist Dawie Roodt. The outcry by funeral-goers including the ex-wife of Nelson Mandela, Winnie Madikizela Mandela, further exposed the ruling party's divide.
But even allies of the ruling party had warned against replacing Gordhan.
Scandals surrounding Zuma include more than $20 million in state spending on his private home - Zuma paid back some funds after the country's top court ruled against him - and the president's links to the Guptas, an Indian immigrant family accused of trying to influence past Cabinet appointments.
Also Thursday, the Economic Freedom Fighters opposition party applied to the country's highest court to order parliament to begin impeachment proceedings against the president for lying to the legislative body.
The EFF called it "a last resort" after parliament, which is dominated by Zuma's ruling African National Congress (ANC), had failed in its duty to hold the president accountable, party leader Julius Malema said. The party on Thursday said it would launch a vote of no confidence in Zuma in parliament.
Zuma in November survived an attempt by senior party members to oust him as president.
The ANC lost control of key metropolitan areas in local elections a year ago, partly because of dissatisfaction with Zuma.
At a news conference after his dismissal, Gordhan urged South Africans anxious about the direction of their country to draw on past protest experience during white rule, saying: "What should the public do?"
"We can't be happy (with the decision to sack Gordhan) because we think that the finance minister was a hard worker".
Deputy President Cyril Ramaphosa was among high-ranking officials in the ruling party who expressed their support for the finance minister.