The poker player saw off 9,300 other players to claim the prize at the Ricoh Arena in Coventry, which hosted the Goliath Poker Tournament from July 27 to August 4.
And to add to the challenge, one of the players 44-year-old Lee had to beat was the former unified world cruiserweight and WBA heavyweight boxing champion David Haye, who received a standing ovation upon taking his seat at the tournament.
Fellow former British heavyweight boxer Audley Harrison also took part in the event.
Lee, a former children’s entertainer who now works as a courier, said he was chuffed to bits with his win and wants to use his winnings to enter more tournaments.
While boxing champion Haye was unable to claim the top prize, he did manage to achieve a 40th-place finish despite only taking up poker a year ago.
Haye had been among the top five players in the tournament at one stage with a chip count of £5.2 million but, with just 12 minutes to go, the boxer was forced to go all in and lost his winnings to a superior flush hand.
Speaking of his appearance at the tournament, Haye said: “One year ago, I travelled to Coventry to announce I’d be taking on the biggest live poker tournament outside of Vegas Grosvenor Casinos’ Goliath.
“It’s been 10 years since I toppled the real life ‘Goliath’ Nikolai Valuev to win the World Heavyweight Boxing Championship.
“A decade later, I again found myself in the same position in David vs Goliath.
“I’d never played a hand of poker in my life! I’ll be the first to admit, I completely underestimated the sheer complexity.
“The months that followed were filled with highs and lows, uncovering a world I never knew existed.
“That simply motivated me to immerse myself in the art, travel the planet to play with and learn from the world’s best - so to come 40th out of 9,300 players is bitter-sweet.”
By Sam Morris.