Staff members at London's exclusive Crystal nightclub are used to high rollers.
But even the most seasoned hosts were stunned Saturday night when one partygoer spent more than £105,000 -- approximately $215,000 -- in less than five hours.
It was near midnight when the mystery spender, rumored to be a Middle Eastern business man, rolled up to the swanky British club, flanked by an entourage of eight women and nine men, and headed straight for the VIP area.
The party started with a simple bottle of white wine.
"He ordered a bottle of Pinot Grigio for £25," or about $50, said Alex Field, a spokesman for the club.
"He then decided to go for a bottle of Dom Pérignon champagne," Field said. "And from there, he basically told the waiting staff, 'just keep the drinks coming.'"
By the time the mystery guest put down his credit card at 4:24 a.m., the tab included 36 bottles of Cristal champagne, totalling nearly $26,000, and a methuselah of the same brand -- equivalent to eight regular bottles -- at more than $60,000.
"This guy came in and just exploded with money," a twenty-something eyewitness and regular of the club, who wished to remain anonymous, told ABC News. "The amount of alcohol coming through was just incredible."
Alex Field said that even given London's notoriously extravagant nightclub scene, he'd never seen spending like this.
"I've been in the industry nine years," he told ABC News. "And I think it's a record."
Fronted by Jacobi Anstruther-Gough-Calthorpe, best friend to Prince Harry and one of London's most recognizable social figures, the blue-themed Crystal Club opened last year, joining a list of London hotspots like Chinawhite, Boujis, and The Cuckoo Club.
A favorite with London's young and rich, famous regulars also include singer Bjork and fashion designer Roberto Cavalli, according to newspaper The Scotsman.
Field said he had seen a surge in big spending in the London club scene over the past few years. Those topping the list, he said, are foreign businessmen.
"I think it's foreigners coming in from Russia and the Middle East," Field said. "They go to St. Tropez, they go to St. Moritz. And they see London as a playground."
Fabienne Mallortigue, owner of the exclusive Club Papagayou in St. Tropez, where a beer goes for $50 and whose clientele is said to include rapper Jay-Z and singer Beyoncé, said Crystal's mystery spender sounded like a dream client.
"We would like to have such crazy people every night," she said from her office at the French club. "But it only happens sometimes."
As some big spenders have already found out, there are risks to such lavish and conspicuous partying.
In 2001, five London traders working in the investment banking unit at Barclays Bank were fired for spending nearly $90,000 on a restaurant dinner to celebrate the closing of a big deal. Their tab included a bottle of 1945 Petrus, priced at around $22,000.
Saturday's bill at Crystal Club also included rarities, such as a near-$20,000 magnum of Dom Pérignon -- equivalent to 1.5 bottles -- delivered to the buyer's table in a platinum gold case.
Such luxury items can't be bought in stores.
"It's impossible to buy a large bottle of Dom Pérignon or Cristal unless you go through a broker, or a big club," said Alex Field. "They're rare."
He added that the quality of champagne improves with larger bottles, because the size of the casing allows the drink more time to mature.
"Champagne really does taste incredible in really big bottles," Field said.
Simon Field, master of wine at Berry Brothers and Rudd, one of the Britain's largest wine retailers, agreed. But he said he doubted that taste was the only reason for the mystery spender's drinking preference on Saturday night.
"These are the most expensive champagnes in the world," Field said. "And the richness that's associated with the champagne is inevitably magnified by the size of the bottle."
Plus, he added, "They just look great on the table."
By the time the anonymous spender ordered the final nightcap, a methuselah of Belvedere vodka, he had invited other club goers to join the festivities and drink along.
"He had quite a party going," said Alex Field.
But the mystery man's entourage weren't the only ones having a good time that night.
Besides nearly $30,000 in tax, the bill also included a $20,000 service charge.
That "tip," Field said, will be distributed among the club's staff.
"Yeah," he said, and laughed. "It was a good night to be working."
Fabiola Antezana and Edward Wrong contributed reporting to this article.