Cyril Ramaphosa, an anti-apartheid activist turned tycoon and politician, has been chosen by the African National Congress as its leader for the next five years.

The battle to lead South Africa’s ruling party, in power for 23 years but hit by declining support and a series of scandals, remained on a knife edge to the very last minute.

Almost 5,000 delegates voted in an internal party election held in a conference centre in Johannesburg. Ramaphosa won with 2,440 votes, against 2,261 for his rival, Nkosazana Dlamini-Zuma.

The delegates’ choice will almost certainly determine the next president of South Africa, due to be decided in an election in 2019, and the trajectory of the "rainbow nation” for decades to come.

The victory of Ramaphosa, 65, will come as a relief to those in South Africa who feared populist and potentially divisive policies from Dlamini-Zuma, a former senior minister and party stalwart who has promised "radical economic transformation”.

It will be a disappointment to those who believe Ramaphosa lacks the will to take measures needed to redistribute wealth and lift millions out of deep poverty. 

As the delegates waited for the result, supporters of both candidates sang, clapped and danced, vying for the loudest, most resonant chants.

An hour after the ANC’s electoral cell was due to take the stage – beneath a huge banner bearing the slogan "towards unity, renewal and radical socio-economic transformation” – some delegates grew impatient.

Delegates from Kwazulu-Natal, a stronghold for Dlamini-Zuma, waved handwritten placards in support of their favoured candidate despite a party order against any partisan visual display.

At the front of the stage, Ramaphosa and Jacob Zuma, the man he will replace as ANC leader, sat side by side, impassive, as aides conferred and rumours of repeated recounts spread around the vast hall. With the results apparently imminent, the two men stood to dance and sing.

The two main contenders represented dramatically different styles as well as ideologies, and the choice made by the ABC’s 54th elective conference is one of the most momentous in South Africa’s recent history, analysts say.

Ramaphosa, currently South Africa’s deputy-president, is seen as the ANC’s best chance of retaining power in the 2019 elections.