When Curtis Woodhouse made his father a death-bed promise that he would one day be a British boxing champion, he can hardly have envisaged the drama that would embellish the climax of that story.

The former Premier League footballer on Saturday night wrote an astonishing closing page to his already special sporting tale when he won the British light-welterweight title in what he insists was his final fight – then hinted strongly that he had bet £5,000 on himself at 50-1.

In front of a packed Ice Arena in Hull, Woodhouse – who made front-page news last year when he confronted a Twitter troll on his own doorstep – outpointed the defending champion, Darren Hamilton, over 12 rounds to win the title on a split decision.

It was difficult to score but close all the way, and the bruised and bloodied winner said through tears at ringside: "I promised my dad before he died that I would win this title and I have. How can I top that? I said beforehand I'd retire, no matter what, and I'm a man of my word. Respect to Darren but tonight was my night.

"There's a rumour going around, which I will neither confirm nor deny, that I had a £5,000 bet on myself at 50-1 – so the drinks are on me. I might go for a Chinese."

A former England Under-21 representative, Woodhouse played more than 350 games over nine seasons for Sheffield United, Birmingham City (where he was a £1million player), Peterborough, Hull and Grimsby. He also manages Northern Premier League First Division team AFC Goole.

He had his first fight in September 2006 but did not have a smooth introduction to the sport. The British Boxing Board of Control suspended his licence for five months after he was convicted for assaulting a police officer. That fiery temperament got him through many of his bouts as he compensated for a lack of experience with raw passion, and he went into Saturday night's fight with the accomplished Hamilton a clear underdog.

Barrelling forward with energy and blind commitment, he forced the champion into an untidy scrap that had the audience on their feet throughout. Even those who thought Hamilton had done enough to win it in the final round did not begrudge Woodhouse his victory.

He is 33, in good health and can look back on a career of 15 wins, two losses and, we are led to believe, a £250,000 bonus from bookmakers who plainly did not rate his chances.

Congratulations poured in from all corners of the boxing community, including a message from George Groves, who challenges Carl Froch for his world super-middleweight title in May: "He has achieved a great feat tonight! Couldn't have happened to a nicer guy."

Woodhouse once said: "Boxing is more addictive than any drug invented." If he can give it up in his moment of triumph, it will define him as a champion with more than just a belt around his waist and a bank balance to ease any lingering pain.