In his maiden speech, Ramaphosa vowed to crack down on corruption -- a reference to the graft-laden reputation of his predecessor, Jacob Zuma
Cyril Ramaphosa, a former anti-apartheid activist turned businessman, was named South Africa's president Thursday and immediately vowed to fight corruption, in a direct reference to accusations levelled against his predecessor Jacob Zuma.
Tainted by scandal, Zuma resigned on Wednesday under intense pressure from the ruling African National Congress (ANC) party that he had dominated during nine years in power.
"Issues to do with corruption, issues of how we can straighten out our state-owned enterprises and how we deal with 'state capture' are issues that are on our radar screen," Ramaphosa told lawmakers in parliament.
"State capture" refers to the alleged corruption of government institutions and state-owned businesses by Zuma's associates.
"Tomorrow we will also have an opportunity to outline some of the steps we are going to be taking," Ramaphosa said.
ANC lawmakers hailed his appointment as president with songs, dancing and a standing ovation.
Ramaphosa, a hugely wealthy former entrepreneur, will deliver his first State of the Nation address to parliament in Cape Town on Friday.
After multiple corruption scandals, economic slowdown and falling popularity among voters, the ANC had threatened to oust Zuma via a no-confidence vote in parliament.
Hours before announcing his resignation, Zuma said he had received "very unfair" treatment from the ANC, which he joined in 1959 and in which he had fought for decades against white-minority rule.
He said he was angered over "the manner in which the decision is being implemented... I don't agree, as there is no evidence of if I have done anything wrong."
- Market boosted -
Zuma, 75, had been embroiled in a divisive power struggle with Ramaphosa, the deputy president.
Ramaphosa won control of the ANC when he was elected as its head in December.
Benchmark South African stocks scored their biggest gains since June 2016 after news that a pro-business reformist would be taking the helm.
The FTSE/JSE Africa All Share Index rose as much as 2.7 percent, while the rand reached its strongest level since February 2015, gaining 0.5 percent at 11.6570 to the dollar in early trade.
"Ramaphosa's arrival in the presidency will be met by a surge in investor and consumer confidence over the coming weeks in anticipation of his reform agenda," said the London-based Eurasia consultancy group.
Zuma, who had no formal education, was jailed on Robben Island for 10 years alongside Nelson Mandela under apartheid and rose through the ranks of the ANC to take power in 2009.
Local media reported that he had been pushing for a resignation deal that included his legal fees to fight multiple criminal charges -- but he denied the allegations in his resignation speech.
One case against him relates to 783 payments he allegedly received linked to an arms deal before he came to power.
Other graft allegations have centred on the three Gupta brothers, who are accused of unfairly obtaining lucrative government contracts and even hand-picking Zuma's ministerial appointments.
Police confirmed on Thursday that an arrest warrant had been issued for one Gupta brother, Ajay.
The political standoff in recent weeks plunged South Africa -- the continent's most developed economy -- into confusion over who was running the country, with last Thursday's annual State of the Nation address postponed at the last-minute.
- Decline of Mandela's party -
Zuma, a Zulu traditionalist with four wives and a proud singing voice, had been scheduled to stand down next year after serving the maximum two terms.
In local polls in 2016, the ANC recorded its worst electoral result since coming to power in 1994 with Mandela at the helm as white-minority rule fell.
Ramaphosa, 65, must revive the economy and crack down on what he has admitted is rampant government corruption if he is to boost the party's tarnished reputation before a tricky general election next year.
He is a former trade unionist and Mandela ally who led talks to end apartheid in the early 1990s and then became a hugely wealthy businessman before returning to politics.