Richard Francis Harry Butcher, 27, is accused of wounding Harry Lee on a night out in Cleobury Mortimer in June 2017.
His trial began at Shrewsbury Crown Court on Monday, and Mr Lee gave his account of that evening.
He said that Butcher attacked him as he was counting his money in an unprovoked attack, after Mr Lee and his friends had been having "light banter" about Butcher's shoes.
Butcher maintains that he hit out in self-defence, and his representative Marc Davies put it to Lee that he had been acting aggressively and swearing at Butcher before approaching him with a pint glass in his hand.
Mr Lee, who was 18 at the time, said that his group had been making fun of Butcher's shoes and comparing them to school shoes as they both stood in an outside area at the Old Lion pub.
Prosecuting, Jamie Scott said that Mr Lee's group arrived at the pub at about 10pm on the night and played darts before settling in the beer garden.
He said: "Mr Lee started to have what some would describe as 'banter' with Richard Butcher; a joke at his expense.
"He made a remark about Mr Butcher's shoes. Mr Butcher began to get irritated with Mr Lee. There was tension building in the air."
He questioned Mr Lee, who said: "I believe it started with the person I was with saying something about his shoes – something along the lines of his shoes, and he took it the wrong way. That's when the tension arose.
"There seemed to be a tension that built up. I saw that he was still looking over so I shook his hand, put my arm around him.
"He responded 'yeah, forget about it'.
"I was trying to be the peacemaker in a situation which in my mind was never ever aggressive, violent, just banter in a pub beer garden which got taken the wrong way."
He said that five to 10 minutes passed and Butcher was still "staring him out". Then as Mr Lee was counting out his money towards the end of the night, he said he felt a blow as if he was hit with a shovel to the left side of his face.
He said the next thing he remembered was Butcher being dragged off of him by both groups of friends.
Mr Lee got up, immediately realised his jaw was damaged and walked home with two friends, he told the court.
The next morning he went to hospital where his fractured jaw was diagnosed and operated on.
Butcher was arrested some time later and told police in interviews he was acting in self defence when he hit Mr Lee.
Mr Davies suggested while cross-examining Mr Lee that he said to Butcher "I like a fight", and swore into his ear when he put his arm around him. Mr Lee denied both suggestions.
Butcher, of Lindridge in Tenbury Wells, denies wounding and the trial continues.