"I was shocked nobody was helping," he said.
"No one else was moving in to stop it. I'm from Vancouver ... where if someone's getting attacked generally you run over to help stop it.
"If I hadn't stepped in, how bad would it have got? Someone could be dead."
Mr Gordon had just left a bar and was looking for a taxi when he first noticed the disturbance, with a man already on the ground being kicked repeatedly in the head.
There were at least two men carrying out the assault and as he tried to stop the man who had put the boot in, he was hit from behind and knocked to the ground.
Protecting his head, he managed to stay conscious, counting each kick before the attackers fled. They left behind four men with minor to moderate injuries, including a 21-year-old student who suffered a broken nose and had both eyes blackened.
Mr Gordon said he was sure he would recognise at least one of the attackers.
Still sporting some grazes and bruises from the assault, he was without fear last night.
"They've already beaten me up, and I'll be leaving [for Canada] in two weeks," he said.
It was understood that police, who are still seeking witnesses and information about the incident, had made no arrests by last night.