Kane Gill struck the victim with a pint glass after losing his temper and carrying out the assault in Bar Fibre.
Leeds Crown Court was shown footage of the assault which took place in the early hours of January 5 this year.
Carmel Pearson, prosecuting, said the victim was a student who had travelled from London with his father on the day of the attack.
He had come to study in Leeds and went out for a farewell meal and drinks with his father who was planning to return to London the next day.
The father and son were sitting at a table in the bar near to Gill and his friends.
Miss Pearson said Gill turned violent after he believed he heard an offensive comment being made.
The defendant's friends became concerned when they saw him holding a glass behind his back and tried to take it off him.
Gill struck the student to the back of the head with the glass.
The 24-year-old then attacked the victim's father when he tried to help his son.
The dad was pushed backwards through some doors and was knocked to the ground.
Gill's friends intervened to stop the attack.
Miss Pearson said: "He realised he was bleeding profusely and then had to watch as his father was attacked."
Gill continued to lash out at the student and his father as he was being restrained by his friends and bar staff.
He was arrested at the bar where he admitted to officers that he had used a glass to carry out the attack.
The student went to hospital and needed stitches to the head wound.
He described in a victim statement how he returned to live in London after the assault because it had made him fearful living in Leeds.
Gill, of The Avenue, Batley, pleaded guilty to unlawful wounding.
Kate Batty, mitigating, said Gill has no previous convictions and described the attack as being out of character for the defendant.
The barrister said Gill was grieving over the death of his father at the time of the incident.
Ms Batty said Gill was sorry for what he had done, adding: "He has expressed a very real insight into the impact upon his victims and he is able to identify the ways in which they are suffering from the offence.
"This is an isolated and wholly out of character incident.
"This is not a person who will trouble these courts again."
Gill was given an 18-month sentence, suspended for two years.
He was ordered to do 300 hours of unpaid work and complete 20 rehabilitation activity requirement days.
Gill was also made the subject of an electronically-monitored curfew order between the hours of 9pm to 7am, for three months.