UEFA president Michel Platini is to remain in hospital on Friday night after fainting in a Johannesburg restaurant, the governing body confirmed.
Platini, who had been suffering from flu-like symptoms, was taken to hospital for tests, none of which showed up any significant problems.
Early reports suggested Platini had suffered a heart attack, but they proved unfounded.
"Michel Platini, UEFA President, fainted this evening after feeling unwell following flu symptoms in the past days," read a UEFA statement. "He was taken to a hospital in Johannesburg for some tests."
"Contrary to some media reports, no signs of any heart-related problems have been found."
"Mr Platini will be kept overnight for observation as a precautionary measure."
Platini is in South Africa for the World Cup, and is scheduled to attend the final between European giants the Netherlands and Spain at the Soccer City stadium on Sunday.
It is unclear whether Platini will now be well enough to go to the match.
"I don't know," UEFA spokesman William Gaillard, who had spoken to a colleague who had accompanied the Frenchman to the restaurant told Press Association Sport.
"The fact is obviously with VIPs they're going to do all sorts of tests, so we don't know when he will be released."
"I was told not to worry. He's fine."
"He has had a bit of a fever recently because he's got a cold and hadn't eaten anything all day."
Platini had reportedly been dining with fellow Frenchman Gerard Houllier and former Scotland manager Andy Roxburgh.
Platini, 55, was a star player for the France national team, who he represented from 1976 to 1987.
He later coached France before moving into sports administration, and in 2007 succeeded Lennart Johansson as president of UEFA, European football's controlling body.