This took place in 2010, and it’s the kind of ending only a CFL game can produce.
Montreal’s Alouettes and Toronto’s Argonauts were tied 30-30, with Montreal in field goal range for a possible win. Under CFL rules, the goal posts are not on the end lines, as they are in American football, but on the goal lines. (The NFL had the goalposts on goal lines as well, but moved them back in 1974) Also, the equivalent of a touchback (most cases) in American football is a rouge in Canadian ball, worth 1 point to the kicking team. That means that if Toronto failed to get the ball out of their end zone, Montreal would get “single” and win the game that way.
Here’s where it gets interesting: a missed field goal can also be kicked (or punted) out of the end zone by the team initially receiving the ball. The team that gets the ball (the inital kicking team) can also to attempt to kick the ball back.
That’s what happened in this game: Montreal missed the field goal, Toronto punted it back, Montreal punted it back AGAIN, then Toronto punted again, but failed to get it out of their own end zone, all of that in one play. Montreal pounced on the ball in the end zone, winning 36-30.
A totally unique finish to a football game that you can get north of the border.