Newcastle United owner and sportswear firm boss Mike Ashley would lie under tables and "take a nap" at meetings he found boring, a finance expert embroiled in a High Court fight with the businessman has told a judge.
Investment banker Jeffrey Blue has sued Mr Ashley after claiming the Sports Direct boss did not stick to a commercial agreement.
Mr Ashley disputes the claim.
Mr Justice Leggatt began analysing evidence at a High Court hearing in London on Monday.
Barrister Jeffrey Chapman QC, who is leading Mr Blue's legal team, told the judge Mr Ashley's business practices flew in the face of "business orthodoxy".
He said Mr Blue referred to Mr Ashley lying underneath tables at "boring" meetings and "playing a game of spoof" to decide who paid an investment bank's fees.
The judge had heard the dispute between Mr Blue and Mr Ashley related to an alleged conversation in a London pub in 2013.
Mr Blue says Mr Ashley made a promise during a meeting in a pub called the Horse & Groom.
He 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.
"Mr Ashley's business practices fly in the face of business orthodoxy," Mr Chapman told the judge in a written outline of Mr Blue's case.
"Mr Blue refers to Mr Ashley lying underneath tables in meetings he found to be boring to 'take a nap', playing a game of spoof to resolve who ought to pay Merrill Lynch's legal fees ... (totalling £750,000) and lavishly entertaining Sports Direct's non-executive directors."
Mr Chapman said the judge would have to consider the relevance of the fact that the discussion took place in a pub.
He added: "Mr Ashley is not an ordinary businessman, does not conduct business in an orthodox way or in business-like environments."
Mr Blue told the judge, in a written witness statement, how he had been a frequent visitor to Sports Direct's head office in Shirebrook, Derbyshire.
He said he had attended several senior management meetings at the Green Dragon pub in Alfreton, Derbyshire.
Mr Blue said: "These meetings were like no other senior management meeting I had ever attended in all my years of investment banking experience.
"It was effectively a 'pub lock-in' with alcohol continuing to be served well beyond closing hours and fish and chips or kebabs being provided throughout the evening.
"On one such evening, in front of his senior management team, Mr Ashley challenged a young Polish analyst in my team, Pawel Pawlowski, to a drinking competition.
"Mr Ashley and Pawel would drink pints of lager, with vodka 'chasers' between each pint, and the first to leave the bar area for whatever reason was declared the loser.
"After approximately 12 pints and chasers Pawel apologised profusely and had to excuse himself.
"Mr Ashley then vomited into the fireplace located in the centre of the bar, to huge applause from his senior management team."
Mr Blue also told of Sports Direct senior management meetings in the Lion Hotel in Worksop, Nottinghamshire.
"Meetings typically commenced in the bar area of the Lion Hotel at around 8pm, with Mr Ashley drinking at the bar while in discussions with various members of the Sports Direct senior management team," he said.
"Mr Ashley would frequently end up taking important Sports Direct related business decisions throughout the evening."
He added: "Mr Ashley and other members of Sports Direct's senior management team frequently consumed alcohol throughout these meetings.
"As noted above, it was Mr Ashley's practice to take important business decisions throughout these meetings, having consumed alcohol, sometimes considerable amounts of alcohol.
"I believe that the reason why Mr Ashley made unlimited quantities of alcohol available at these senior management meetings was a deliberate strategy to encourage his senior managers to speak "more freely" than might otherwise be the case in a more formal meeting environment.
"Such an approach is typical of Mr Ashley's personality and business style."
Mr Blue said he first met Mr Ashley when working for Merrill Lynch in 2006.
"Mr Ashley was like no other client that anyone at Merrill Lynch had ever come across," added Mr Blue.
"By way of example, his ability to express boredom and frustration during client meetings knew no limits, including various episodes where he would lie underneath meeting room tables to 'have a nap'."
Mr Blue said the lay-out of the Sports Direct head office left "no doubt as to the concentration of power" and told the judge how Mr Ashley was positioned at the centre of an "almost entirely open plan environment".
Mr Ashley, who is at the High Court hearing but not expected to give evidence until later in the week, disputes Mr Blue's claim.
David Cavender QC, who leads Mr Ashley's legal team, told the judge that Mr Blue's claim was an "opportunistic try on".
He said, in a written outline of Mr Ashley's case, that there was "contemporaneous evidence of the purported agreement".