Lee Ryan's claim that he punched Mr Ibrahim in self-defence was rejected
Singer Lee Ryan has been found guilty of punching a taxi driver in the head and fined £500.
The former member of boyband Blue had denied common assault during a row over a traffic accident on New Year's Eve in Oxted, Surrey last year.
Naeem Ibrahim was attacked after Ryan's fiancee drove into the back of his cab.
After a trial at Guildford Magistrates' Court, District Judge Bob Booker fined Ryan, 25, and ordered him to pay £300 in compensation and costs of £450.
He must also pay a £15 surcharge which goes towards victims of crime.
'Tennis ball' lump
Ryan, whose former group had a string of number one hits including All Rise, launched the attack on the cab driver following the crash at traffic lights.
The accident happened while Samantha Miller, 24, was driving the couple to a New Year's Eve party at his mother's house.
The court heard Ryan felt Mr Ibrahim was trying to claim for damage which was already on the taxi, that he refused to pay for.
In the resulting argument, the pair pushed each other before Ryan punched Mr Ibrahim and he slumped to the ground.
The court heard the victim was left with a lump "the size of a tennis ball" behind his ear and was off work for three weeks.
Ryan told the court he was often a target in public because of his fame and claimed that he punched Mr Ibrahim once in self-defence after he came at him with his "fist raised".
District Judge Booker told Ryan he rejected his claim of self-defence but accepted that it was only one punch.
He added: "I have to accept the defendant's past experiences may colour his judgment when dealing with an awkward situation.
"I do regard this a situation where you over-reacted to a position you were put in.
"Although this was in essence an attack upon a vulnerable person that serves the public, I do take into account the injury was minor and appears to have come about as a result of what you did rather than the actual assault itself."
As he left court, Ryan said: "I am upset at the judge's decision. I am not a violent person and I don't want the public to think that.
"I get a lot of people wanting to fight me but I am not like that. But the judge has made his decision and there's not a lot I can do about that."
He had earlier explained how his celebrity status had made him a target and he had previously moved to America and lived in Venice Beach for a year and a half to escape press attention.
He said he shuns going out to nightclubs now to avoid drunk young men who target him and instead prefers to stay in with his fiancee.
Ryan, from Bromley, was convicted of criminal damage to a photographer's camera in 2004 following an altercation outside a nightclub. He also accepted a police caution for assault relating to the same incident.