Harlequins legend and former British and Irish Lions star Ugo Monye were amongst the union team behind the mauling, while league's team of traders for the day included former Great Britain international Garreth Carvell.
"It's quite bizarre, I just gave a ticket and apparently that's worth £400,000," marveled Monye. "It's exciting. You see a lot of ex-rugby players working in the City. They're very generous and willing to give opportunities, like this one."
In an event that raised £20,000 for charities Restart Rugby and Rugby League Cares, players swapped the usual surrounds of shorts, studs and mud for stacked trading screens and pinstriped suits.
Yet despite some obvious differences between the professions, many aspects remain the same between the changing room and the trading floor including the competitiveness and camaraderie between the teams.
"After watching the Wolf of Wall Street and The Big Short, I found this quite interesting," said London Irish flanker Conor Gilsenan. "I'm sure they're keeping it quite PG in front of us today but there seems to be the same mentality, a lot of lively characters."
Restart Rugby, the official charity of the Rugby Player's Association, offer players both post-playing career planning, education and financial support to deal with catastrophic injury — an increasing risk for today's larger than ever before players.
"When you get a few knocks you realise how fickle it [a playing career] is," said Gilsenan, whose playing time was significantly curtailed by concussions and other injuries last year.
The City remains a popular destination for many players. "The disciplines are already inside of them, they've got the right mantra they work their lives to," said Tony Rea, former chief executive and head coach of the London Broncos. "Their challenge afterwards is to maintain those core soft skills and work to learn hard skills."