Judge David St. Pierre said Jonathan Mahoney was caught up in the moment, enjoying the mayhem and chaos of the 2011 riot when he gathered with a mob outside the Hudson's Bay Store on Georgia Street in downtown Vancouver.
Mahoney was using a metal pole to destroy the store's windows when Robert MacKay, a man who would later be awarded by the Vancouver Police Board for his bravery, intervened and tried to stop the mob.
Mahoney turned his attention to MacKay, beating him and throwing him to the ground.
Video posted on the internet showed a number of people swarming MacKay, some kicking and punching him, others pushing him to the ground and dousing him with bear spray.
In the aftermath of the riot, police identified Mahoney as their most-wanted suspect.
Mahoney left Vancouver for Manitoba and then Newfoundland, eventually ending up in Saskatchewan, where police arrested him.
In July, Mahoney pleaded guilty and apologized for his actions, calling the riot "a very dark day in the history of this beautiful city." He also praised the actions of the Good Samaritans who tried to stand in the way of rioters.
On Thursday, Judge St. Pierre said he took into account previous sentences for others involved in the Good Samaritan beating, as well as Mahoney's remorse and the fact that he was a skilled young ironworker.
Mahoney has already begun serving his sentence at the Fraser Regional Correctional Centre in Maple Ridge, B.C.
In May, two other men were sentenced for attacking MacKay during the riot. Last September, police said 15 people were charged in the assault.
In total, more than 100 admitted or convicted rioters have received sentences ranging from discharges to more than a year in jail.