A five-a-side soccer player who punched an opponent leaving him with brain damage walked free from a court today.

A jury took less than an hour to clear Andrew Walker,22, after other players said that victim Darren Mitchell, 32, earlier repeatedly punched a man he was marking.

Mr Walker said that he struck Mr Mitchell to end his attack on "defenceless" Shaun Lyons, but Mr Mitchell catapulted backwards into a wall causing brain injuries.

He was in hospital for 13 days after the incident during a league match at Saltburn Leisure Centre between his pub side The Clarendon, Marske, and North East Tyres and Exhausts where Mr Walker was a supervisor.

Mr Walker, of Foster Street, Brotton, said during his three-day trial at Teesside Crown Court that he was horrified when he saw Mr Mitchell, a telecommunications engineer for the European Golf Tour, lying unconscious.

He added: "It was the only way to stop the assault on Shaun because he was defenceless. It just happened , I was not thinking."

Shaun Lyons said that he was punched about half a dozen times on the back of his head by Mr Mitchell, of Arthur Street, New Marske. He added: "Afterwards I had a pain in my jaw and a lump on my head. When I looked around he was on the floor, although I did not see how he got there."

Mr Walker was found not guilty of causing grievous bodily harm on May 13 last year.