Newcastle United owner and Sports Direct boss Mike Ashley is preparing to give evidence at a High Court trial after being sued by a finance expert who says he reneged on a £15 million deal.
Investment banker Jeffrey Blue says Mr Ashley promised to pay him £15 million if he used his expertise to increase Sports Direct's share price to £8 a share.
He says Mr Ashley paid only £1 million - and he wants £14 million damages.
Mr Ashley denies the claim and says Mr Blue is "trying to take me for £14 million off the back of some drunk banter".
He is scheduled to start putting forward his side of the story on Wednesday.
A judge began analysing evidence, at a hearing in London, on Monday.
Mr Justice Leggatt has heard that the dispute between Mr Blue and Mr Ashley relates to a conversation in a London pub in 2013.
Mr Blue says Mr Ashley made a promise during a meeting in the Horse & Groom four years ago.
The investment banker has told the judge that Mr Ashley is a "serious businessman".
He said the work ethic at Sports Direct was "like nothing else I have ever seen".
But he said Mr Ashley sometimes did business "in unorthodox ways and in unusual venues".
Mr Blue has told how Mr Ashley vomited into a fireplace after a Sports Direct senior management meeting which was "effectively a pub lock-in".
He said Mr Ashley would nap under tables at "boring" meetings.
Mr Blue also told how Mr Ashley had lambasted Sports Direct's non-executive directors after a dinner at a London restaurant three years ago.
"The dinner commenced with Mr Ashley ordering ... drinks, in this case the most expensive red wine available from the sommelier (Richebourg at around some £3,000 per bottle)," he said.
"When supplies of this had been exhausted, Mr Ashley continued with the Penfolds Grange (£875 per bottle).
"Following dinner, the party retired to Les Ambassadeurs, a London casino where Mr Ashley and the non-executive directors played at the roulette table."
He said the next day Mr Ashley complained about being lectured about corporate governance.
"Mr Ashley (was) outraged that the non-executive directors were, in his view, hypocrites," said Mr Blue.
"Mr Ashley said words to the effect of: 'How dare they lecture me about corporate governance when they're all happy to sit around and get p***** on £3,000 bottles of wine at the company's expense and then go to a casino, not believing their f****** luck when they wake up the next morning with a £20,000 casino chip in their pocket or purse."
Mr Blue came under attack from Mr Ashley's lawyers as he gave evidence during the second day of the hearing on Tuesday.
Barrister David Cavender QC, who is leading Mr Ashley's legal team, accused Mr Blue of ''making up evidence''.
Mr Ashley watched from the back of the court as Mr Blue was questioned by Mr Cavender.
Mr Cavender has described Mr Blue's claim as an ''opportunistic try-on''.
''The claim appears to have been issued on the basis that the threat of negative press alone would compel Mr Ashley to settle,'' he has said in a written outline of Mr Ashley's case.
''In truth, there was no purported agreement, and Mr Blue could not have thought so at the time.''
Mr Cavender said Mr Ashley ''fairly'' said he could not recall details of conversations in the Horse & Groom ''particularly in the light of the amount of drinking''.
''He does recall 'that there was a lot of banter and bravado','' said Mr Cavender.
''He does not recall any discussion about whether Mr Blue would be paid a sum of money if the share price reached £8 a share.''
Mr Cavender added: ''He says if there was 'it would have been obvious that he was joking'.''
Mr Ashley has told the judge, in a written statement: ''I can't believe that (Mr Blue) is now trying to take me for £14 million off the back of some drunk banter that he is seeking to engineer into something more.''