Mr Ramaphosa, the nation's deputy president, defeated former cabinet minister Nkosazana Dlamini-Zuma, Mr Zuma's ex-wife, after a marathon voting process.

The 65-year-old is now in a strong position to become president after elections in 2019.

He smiled and hugged other party officials as the results were read out at the ANC's 54th National Conference in Johannesburg.

After his narrow victory he vowed to fight rampant corruption and revitalise the South African economy, a message hailed by foreign investors.

Mr Ramaphosa was a key ANC negotiator and strategist during South Africa's transition to democracy.

He rose to political prominence as a union boss who went on to became a successful businessman and is now one of South Africa's richest people.

His  leadership battle with Ms Dlamini-Zuma, 68, caused fierce political infighting and  raised fears the party may split before the elections.

The vote has been decribed as the most pivotal moment for the party since it launched black-majority rule under Nelson Mandela 23 years ago.

Ms Dlamini-Zuma, the president's preferred candidate, had campaigned on pledges to tackle the racial inequality that has persisted since the end of white-minority rule.

Mr Zuma's presidency has been tainted by corruption accusations.

He has always strenuously denied the claims but there is no doubt the image of 105-year-old liberation movement has been tarnished as a result.