Prosecutor Elen Owen claimed the defendant, who works as a fencing contractor, wanted revenge on Barlow after an incident earlier in the game.
The court heard that Williams had complained to the referee about Barlow following a 50-50 challenge.
Miss Owen asked the defendant: 'You wanted to hurt him, didn't you?'
He replied: 'No.'
Giving evidence, Barlow said: 'He was getting angry. He was shouting at me ... I saw Williams coming towards me from behind on my right.
'I tried to jump out of the way. I couldn't get high enough out of the challenge. He's caught me with his studs in the middle of my shin. All I remember was looking up and seeing my leg flopping and going into the ground.'
Williams told the court: 'It was just a freak accident. I just gave it the extra bit more and his leg snapped. I got up and heard him scream.'
But match referee Mark Stokes said: 'That challenge was probably the worst one I have seen in my time as a referee. It wasn't a challenge; it was a kick. There was no attempt to kick the ball.'
Williams denied there was any intent but a jury at Caernarfon Crown Court unanimously concluded the tackle was deliberate.
Judge Huw Rees said the defendant had been convicted on overwhelming evidence and spectators at the match had witnessed his 'brutish thuggery'.
Miss Owen said Barlow had not been able to return to his job at Marks and Spencer since the attack 10 months ago.
He had to have rods inserted in his leg and had suffered nightmares after seeing it 'flap from side to side'.
Williams, from Wrexham, North Wales, was found guilty of grievous bodily harm and jailed for 12 months.
