Scott Marsden, known as Scotty, needed urgent medical attention during an English title Fight at Leeds Martial Arts College in West Yorkshire on Saturday.
The 14-year-old, who won a 50kg gold title at the World Kickboxing Association (WKA) finals in Spain, was rushed to hospital after blacking out in the final seconds.
The title fight had been close with just one point separating two of the country’s best young fighters – however there was nothing to suggest the contest needed to be stopped up to that point.
Family friend, Charlotte Rowlett, paid tribute to the teenager after announcing that he died ‘surrounded by his family and people who love him’ yesterday.
West Yorkshire Police said the incident is not being treated as suspicious.
A force spokesman said: ‘At 1.20pm on Sunday, police were contacted by medical staff at Leeds General Infirmary reporting a 14-year-old boy who was in a critical condition after collapsing during an organised kickboxing contest at Alexandra Mill, Morley, on Saturday night.
‘Inquiries are being carried out into the circumstances.’
Scott was a member of Marsden’s All Styles Kickboxing, in Sheffield, which was set up by his father, Simon Marsden, and his uncle Darren Marsden around eight years ago.
The club posted a statement on Facebook on Sunday, which said training was cancelled until further notice.
A post written earlier in the day said: ‘Unfortunately, (Saturday) night’s English title fight had to be stopped due to Scotty needing immediate medical attention.
‘There was no way to foresee the fight ending in such a way as at no point were either ever in any overwhelming danger from each other.
‘Everyone is still in shock as there were simply no signs to suggest the fight needed to be stopped.
‘The referee stepped in to protect Scott as soon as he could, which meant Scott did not hit the canvas and was laid down and straight into recovery position.
‘Let’s please come together to support the Marsden family at this incredibly difficult time.
‘No amount of money can ease the pain but let’s please do what we can.’
Ms Rowlett has since set up a fundraising page for the family.
She said: ‘Everything Scotty did he did with passion and a confidence that was a pleasure to behold, he was the most wonderful, talented boy and the loss of him will leave a hole in so many people’s lives.
‘Scott was not only a kick boxer though, he is a son, a brother, a grandson, a nephew, a cousin and a friend.
‘No amount of money can take away the pain his family are feeling today and always, but no family should ever have to cater for coping with the loss of a 14 year old boy, with his whole life ahead of him.’
Scotty will always be in our hearts & our thoughts and we miss you dearly.
‘A true champion in every way who’s energy & positivity affected everyone he met.
‘Rest now Scotty lad.’
The Leeds Martial Arts College is now closed until further notice.
Scott had only just returned to the sport after breaking his tibia and fibia in a fight in late October last year, just two days before he was due to fly to Italy with his teammates for the World Championships.
Writer: eorgia Diebelius for Metro.co.uk