Dlamini-Zuma emerged victorious after four gruelling rounds of voting conducted behind closed doors.

She clinched the first round by a narrow margin - 27 votes against Ping's 24. However, she increased the margin in the second round when she received 29 to Ping's 22 votes.

But it was in the third round that she took a decisive lead, garnering 33 votes as her challenger fell to only 18 votes.

A third round loss immediately eliminated Ping from the race and Dlamini-Zuma proceeded to the fourth round uncontested.

She won it by 37 votes, giving her more than the required two-thirds majority.

This makes Dlamini-Zuma the first candidate from southern Africa and the first woman to lead the continental body.

After the outcome was announced, South African ministers, ambassadors and government officials broke into a song in celebration.

ANC secretary-general Gwede Mantashe said last night that Dlamini-Zuma's achievement was not only hers, but also for the continent.

"The results are not about her, it's about what we want to put to the AU. We want to take it out of the hands of the colonisers. We have a lot of confidence in her and as a capable leader she will do the job."

He said her election should not be viewed as a loss to South Africa. "We have given the continent the best and we are all going to benefit," Mantashe.

Angie Motshekga, ANC Woman's league president, said: "This is indeed exciting for the ANCWL and women in the continent. Her election is a victory for gender struggle in the continent."

The DA also welcomed Dlamini-Zuma's appointment, saying that she "can lead a new era of a prominent place for Africa in the international agenda".

Her decisive victory came despite attempts by Ping's supporters to discredit South Africa's candidacy by launching a stinging attack on President Jacob Zuma, accusing him of trying to use his former wife to sell the continent to global financial institutions.

Ping's campaigners - who dubbed themselves the "African Advisory Board" - wrote to all heads of state warning them not to vote for Dlamini-Zuma.

They accused Zuma of using Dlamini-Zuma as a Trojan horse for international financial institutions. "Accepting Mrs Zuma's candidacy amounts to fully selling out our continent ," they said.

The Zumas divorced in 1998.

The lobbyists also said the fact that the Reserve Bank had private shareholders was proof that the country was not a fully sovereign state and should not be allowed to field a candidate for the position.

"The central bank is privately owned since the apartheid era by an Afrikaner coalition.

"How could President Jacob Zuma, notoriously unable to dismantle the Afrikaner infrastructure that still controls the South African economy through control of the central bank, claim to assume and defend the union project of Africa? Aggravating circumstance is that he wants to do this through his ex-wife for his domestic political agenda."

Dlamini-Zuma squared off with Ping in January but neither could muster enough votes to secure a two-thirds majority.

SADC had been lobbying hard for Dlamini-Zuma ever since.

She was also given a boost by news that West African regional body Ecowas had been unable to agree on a nominee.

Opening the heads of state summit yesterday, AU chairman, President Boni Yayi of Benin, urged African leaders to settle the matter once and for all. - Additional reporting by Dominic Mahlangu