Cyril Ramaphosa told roughly 5,000 members of his African National Congress party gathered outside Johannesburg for the much-delayed climax of a five-day conference that the public wanted the "leadership to be united".
President Jacob Zuma has stepped down as head of the party but can legally remain as president until 2019 -- the end of his term.
"Speculation was rife that the 54th conference of the ANC would either not take place or collapse on the very first day," Ramaphosa said, referring to the bitter legal battles over which members would be permitted to vote for the new leader that threatened to overshadow the gathering.
"We are still here standing 106 years later -- we are alive, we are leading and we are here to stay."
Ramaphosa narrowly won the leadership vote on Monday after an acrimonious race that exposed rifts within the one-time liberation organisation between his camp and that of rival Nkosazana Dlamini-Zuma.
"I wish to pay tribute to comrade Nkosazana Dlamini-Zuma, who contested the position of President, for the manner in which she demonstrated commitment to our movement," Ramaphosa said.
Dlamini-Zuma is a former African Union Commission chair and is the ex-wife of Zuma which led to accusations that her victory would have meant a continuation of his deeply divisive tenure.
Zuma's reign has been plagued by corruption scandals, a slowing economy and anger at the once-omnipotent ANC.
'People of South Africa want action'
"President Zuma -- one has been accustomed to you closing conferences of the ANC... and I feel like I'm walking in your shoes tonight," said Ramaphosa.
"One has to get used to this."
In a restrained maiden speech that avoided score settling, Ramaphosa vowed to crack down on corruption, boost the economy and heal the divided party.
"We must also act fearlessly against alleged corruption and abuse of office within our ranks," he said without making any specific allegations.
The ANC, which has ruled since 1994 when Nelson Mandela won the first multi-racial vote, could struggle to retain its grip on power in the 2019 election due to falling public support.
Ramaphosa, 65, is a former trade unionist leader who led talks to end white-minority rule in the early 1990s and then became a multi-millionaire businessman before returning to politics.
He is often accused of failing to confront Zuma while serving as his deputy since 2014.
"The people of South Africa want action, they do not want words," Ramaphosa said to a sea of delegates from across the nation dressed in the official ANC colours of yellow, green and black.
"In recent times, we have seen the ANC at its worst. We have seen an organisation divided against itself," he said, adding people were tired of the party serving "vested interests".
He gave a tepid endorsement of the conference's resolution to press ahead with a controversial policy of land redistribution without compensation in favour of landless and poor South Africans.
jpegMpeg4-1280x720"This conference has resolved that expropriation of land without compensation should be amongst the mechanisms available to government to give effect to land reform and re-distribution," he said to applause.
"It has also been resolved that we ensure we do not undermine the agricultural production or the economy -- that is what is important."
Eyewitness? Submit your stories now via social or:
Email: eyewitness@pulse.ng
![The woman was recorded, among others, while bathing [BI]](data:image/svg+xml;charset=utf8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'300'%20height%3D'172'%20data-ring-placeholder%3D'1'%3E%3C%2Fsvg%3E "The woman was recorded, among others, while bathing [BI]")
