Khaya Mthethwa (25) won a nationwide vote against 23-year-old Melissa Allison on Tuesday, ending the dominance of racial minorities since the contest, based on Britain's Pop Idol, launched in 2002.
The gospel-influenced Mthethwa, from Durban, had been the favourite to win and was backed by a vociferous campaign. Some fans reportedly bought multiple mobile sim cards so they could vote more than once.
Mthethwa's season eight victory was announced at a gala event in Johannesburg featuring performances by local artists. Almost three-million South Africans voted over the past week, M-Net said.
Idols has become a cultural litmus test 18 years after the end of apartheid, with viewers apparently tending to vote along racial lines.
White people make up less than one in 10 of South Africa's population. But black contestants are said to be disadvantaged because Idols is shown on a subscription channel and viewers must pay to vote, meaning that voters are disproportionately from the white middle-class.
When there have been black winners of the series, they were coloured people.
The Times on Monday noted in each of the previous seven seasons of Idols, M-Net has had to defend itself against allegations of vote-rigging and racism.
"Smelling blood, black celebrities have, to use political-speak, canvassed and mobilised voters on Mthethwa's behalf, sensing that he is on the verge of changing the trend," the paper said.
The famous picture depicting thousands of women from the ANC Women's League marching against apartheid-era pass laws had been digitally altered to read "SMS 08 to 37400. Vote for Khaya", the Times added.
A change in the racial trend seemed on the cards two years ago but strongly tipped Lloyd Cele was eventually defeated by Elvis Blue. They split the winnings.
Mthethwa takes home a prize package worth almost R1-million, including a recording contract with Universal Music South Africa.
He will start work on an album in the next two weeks. – © Guardian News and Media 2012