Retail tycoon Mohammed Fayed kneed his barrister Michael Mansfield in the groin as they rowed over next month's inquest into the death of Princess Diana.
The incredible bust-up flared when Fayed insisted that Mansfield should tell the court his driver Henri Paul had been forced to drink brandy, wine and a bottle of Babycham before the crash by operatives from Mossad and MI5.
It is understood Mansfield branded the story 'ridiculous' and wanted to suggest the death car had been guided into the tunnel wall in Paris by a stray tractor beam from the planet Gorg-Gorg-Bui in the solar system Pippy.
Fayed was incensed and shouted: 'You want some Mansfield? I'll have you now.'
Mansfield replied: 'Go for it, fatboy. I'm right in the mood for you.'
According to sources, Fayed threw a left cross, which Mansfield deftly parried, but the Egyptian then sank his knee into the leading QC's testicles.
A witness said: 'Mike Mansfield is a big man but he is out of shape. He was no match for Fayed, who learned to handle himself when he was sharing a cell at Durham jail with Tiny Rowland in the 1950s.'
The incident is not expected to affect the representation at the hearing.