JOHANNESBURG >> President Jacob Zuma of South Africa, a master tactician who survived a string of corruption scandals and harsh court judgments during his nearly nine-year presidency, agreed on Wednesday night to step down, repudiated by the governing African National Congress Party, threatened by a no-confidence vote in Parliament, cornered by opposition parties and abandoned by millions of voters.

In an address to the nation Wednesday night, Zuma said he was resigning even though he disagreed with the party’s decision ordering him to do so.

“I have therefore come to the decision to resign as president of the Republic with immediate effect, even though I disagree with the decision of the leadership of my organization,” he said at the end of a lengthy address on television. “I have always been a disciplined member of the ANC.”

It is a humiliating end for Zuma, a charismatic anti-apartheid hero who was imprisoned on Robben Island with Nelson Mandela and was once the ANC’s intelligence chief. Cyril Ramaphosa, the deputy president whose election as ANC leader in December set off a power struggle with Zuma, immediately became acting president.

Initially Zuma’s presidency inspired hope in millions of South Africans, especially the poorest. But, tainted by numerous accusations of misconduct, he came to symbolize the corruption that flourished during his time in office.

Influence-peddling in his administration was so widespread, according to the nation’s former public protector, that it became a form of state capture in which Zuma’s business partners or friends influenced government decisions in their personal interest.

Now, his departure as president leaves South Africa with a disillusioned electorate, a weakened economy and a tarnished image in the rest of Africa.

Only hours before his resignation he sounded defiant and aggrieved during a live interview with the state broadcaster SABC, after party leaders threatened to hold the no-confidence vote on Thursday. He indicated strongly that he would not resign, saying that the party’s effort to pull him from office was “unfair,” that he was being “victimized,” and that he had done nothing wrong.

But by Wednesday night, whatever narrow paths of escape he may have hoped for earlier had closed.

On Thursday, Ramaphosa is almost certain to be chosen by Parliament to become the nation’s fifth president since the end of apartheid in 1994; all have been members of the ANC.