Nigel Thew, whose ankle was broken in three places during the incident, was dismissed after he marched the man off the bus.
The 52-year-old explained to The Metro: "This guy threatened to put a bottle in my face – he was holding it down by his side and had his fingers around the neck of the bottle.
"Nobody complained about my actions – not even the passenger."
Mr Thew ordered the man off the bus in Saltdean, East Sussex last October when other passengers feared for their safety. However the drunk refused to leave, meaning Mr Thew was forced to grab the man's jumper and walk him off the vehicle.
Both fell over and Mr Thew broke his ankle but, despite his injury, he pinned the man to the ground until police came to arrest him.
"Nobody complained about my actions – not even the passenger"
While he was recovering at home from his injuries, Mr Thew was told he was contacted by his employer and fired.
Martin Harris, managing director of Brighton & Hove Bus and Coach Company, said: "We have clear CCTV recordings of what takes place on our buses. Such serious decisions would not be taken without clear evidence.
"Issues of data protection and confidentiality prevent me saying more."
The passenger, meanwhile, pleaded guilty to using threatening words when the case came to court in November. He was fined £37 and ordered to pay £105 costs.