It was in the famous old Fitzroy Lodge amateur boxing club, underneath the arches in Lambeth, South London, and barely half a mile from the Houses of Parliament, that David Haye and Adam Booth first met.

In a business where the closest of partnerships often end up in the law courts, the pair have an unusually tight bond. Booth is trainer, manager and friend.

Booth, 41, was training a seasoned professional, Chris Okoh, that day in 1996, when Haye, who was only 15, volunteered to spar. “Chris was a Commonwealth champion, but anyone watching would have thought that the Commonwealth champion was David,” Booth said. “He looked very special.”

It was a meeting that would change both men’s lives. Booth had begun training after his own hopes of boxing professionally were thwarted.

“I boxed as a light-welterweight at the Lynn [amateur boxing club in South London],” Booth said. “I had 48 bouts and won 40. I agreed to turn professional with Mickey Duff, but my career ended when I broke my leg playing football.”

While training is a poor second-best to competing for many, Booth discovered his calling when he met Haye, who shared his love of the sport.

They have enjoyed good moments and bad. It was Booth who threw in the towel to rescue Haye during his only professional loss, to Carl Thompson in 2004. Booth was at Haye’s side when the demise of the British arm of Setanta Sports, the broadcaster, put on hold dreams of developing their own promotional company, Hayemaker. And Booth was there, with a tear in his eye, in Nuremberg on Saturday, after coming up with the strategy to take the WBA heavyweight title from Nikolay Valuev.

“Adam is like a brother,” Haye said. “Everyone in the team is very close, everyone has their role and we come together and produce the goods. It’s always good to have someone you can trust. Boxing is riddled with guys who you can’t trust.”