It was Mario 64.
In front of a crowd, all of us unaware of what was happening. I got to Bowser, in what was to be the first of many fights. At the time we all thought I was at the end, and it had come as quite a surprise, replete with actual oohs and aahs.
Somehow I divined his first attack, avoided it, and, seeing no other option, I ran 'round to behind him, grabbed him by the tail, and threw him off of the mountain. Everyone went NUTS! I was still stunned, really. I had just run on instinct.
I'm not much of a fan of the mario series, really.
But as moments go, it was pretty sweet!