The Raiders celebrate the 1989 grand final.

Canberra's 1989 extra-time grand final win over Balmain has been declared the game's greatest premiership decider after a poll conducted by the Men of League Foundation.

The epic grand final, in which the Raiders triumphed 19-14 after a Chris O'Sullivan field goal and a Steve Jackson try during extra time, was chosen ahead of North Queensland's 2015 golden-point defeat of Brisbane and Newcastle's last-gasp 1997 victory against arch rivals Manly. 

The result was announced at the foundation's annual gala dinner at the Westin Hotel on Wednesday night, which was attended by current and former stars, including Cowboys playmaker Michael Morgan and ex-Balmain prop Steve Roach.

Men of League also announced the milestone achievement of $500,000 spent on wellbeing support to the rugby league community so far this year at the charity event, which raises funds for those who are experiencing hardship.

The Balmain Tigers after the 1989 grand final.
The Balmain Tigers after the 1989 grand final. ©NRL Photos

The foundation's national wellbeing manager, Jessica Macartney, said reaching the milestone with more than four months of the year remaining was an amazing feat.

"That is half a million dollars' worth of medical equipment, utility bills, car modifications, food and fuel for those within the rugby league community experiencing hardship," Macartney said.

"But more importantly the Men of League Foundation has provided hope and support to rugby league families in times of real distress and need.

"Although this is something to be tremendously proud of, we know that the job is not done yet. There are always more people to help and we can't do it without the rugby league community's support."

Men of League Foundation CEO Stephen Lowndes also congratulated the rugby league community for their extensive support of the foundation's cause.

Balmain's Steve Roach in the 1989 grand final.
Balmain's Steve Roach in the 1989 grand final. ©NRL Photos

"The annual gala dinner has once again proven why it is a signature event on the rugby league community's social calendar," he said.

"The 1989 grand final between Canberra and Balmain took out the coveted Greatest Grand Final, as guests were treated to exclusive insights from Balmain legend, Steve 'Blocker' Roach.

"As well as the unveiling of the Greatest Grand Final, the gala dinner highlighted the outstanding work which has been carried out by our incredible volunteers, as well as announcing the incredible achievement of $500,000 distributed to the men, women and children of the rugby league community in 2018. 

"It has been a tremendous year thus far for the Men of League Foundation and we are excited by the opportunities that lay ahead for the rest of 2018 and beyond."