It all went down at BC Place Stadium in British Columbia, Canada, where the Toronto Argonauts faced the Winnipeg Blue Bombers for the 111th Grey Cup (think their Super Bowl.)

The place was packed with over 52,000 fans (including Prince Harry, Jason Kelce and the Jonas Brothers) when a woman jumped on the field in the fourth quarter.

Several fans in the crowd captured it on video (they're online), showing the brunette with no clothes on ... although she was holding a coat.

The woman appeared to be having the time of her life streakin' as she waved to the crowd ... who also seemed to be enjoying themselves.

This time, there was no violent ending -- no one was tackled -- 'cause the woman walked up to security, who escorted her off the field.

As for the game, it was a fun one ... the underdog Argonauts beat the Blue Bombers, 41-24.