Luton Crown Court was shown footage of the attack at The Nags Head in Dunstable last May after the man allegedly called Mr Dixon a "fatso".
Mr Dixon, 53, who lives in the town, denies causing actual bodily harm.
The court was told Mr Dixon will be claiming he struck out in a "pre-emptive strike" in self defence.
The attack by the former footballer, who also played for Luton Town, Southampton and Reading, was captured on the pub's CCTV at 12:40 BST on 15 May 2014.
In the footage, Mr Dixon is seen punching 38-year-old father-of-two Ben Scoble in the face, sending him to the ground.
He is then shown bending over the alleged victim, from east London, and delivering more punches and kicks.
Mr Dixon then removed an empty pint glass that was still in Mr Scoble's hand and placed it on the bar before walking out.
It is alleged the brawl occurred after Mr Scoble swore at Mr Dixon and refused to leave his seat where the ex-striker and his girlfriend were previously sitting.
The jury was told Mr Scoble suffered a cut lip and two of his front teeth were loosened.
Simon Stirling, prosecuting, said Mr Dixon told police he had continued to hit the other man "to make sure he stayed down and no longer presented a threat to him".
Earlier in the night, it was claimed Mr Scoble approached Mr Dixon in the pub's lavatory and said: "You're a drug dealer, have you got any drugs?".
He told the court he had no recollection of it and denied swearing at Mr Dixon.
The trial continues.
Former Chelsea and England centre forward Kerry Dixon knocked a drinker off a bar stool and punched and kicked him on the ground, a court has heard.