A post left on a newspaper's internet forum at 10.28am on Friday morning - 90 minutes before the draw took place in Nyon - correctly predicted the entire quarter-final draw.
When all four ties predicted in the post came to fruition it caused fevered internet speculation that some sort of manipulation might have taken place.
But a Uefa spokesman said: "It is just a lucky guess.
"I have been in touch with people internally and they are quite surprised. They find it a little ridiculous actually.
"The results of the draw and the practice draw were completely different, and I think it was just pure luck that this guy could get them all right.
. "That's the only explanation we can give."
Former Russia goalkeeper Rinat Dasaev pulled the balls out of the hat during the draw, which was televised live, with Uefa general secretary David Taylor watching on.
Uefa are confident that the entire procedure was impossible to rig.
"It's a draw that's open to the public and club representatives. The balls are all of the same colour and there are no distinctive marks on them," added the spokesman.
"I was just 10 metres away and what was drawn was also read by Mr Taylor. It (a fix) is impossible."