My greatest triumphs have come from pickup basketball games. Somehow, I finally developed a reliable 3-point shot in my 30's and I've gotten to hit a ton of game winners over the past few years. I definitely don't look like a formidable basketball player and the other team (or player) can get buried pretty quickly before they start really guarding me.

An additional almost triumph was when I almost won a HS 1-1 tournament as a 5'2" freshman, before finally losing to the varsity center in the championship.

Shocking defeats and hilarious moments seem to come together.

1. In a middle school cross country race, my friend and I (same team) happened to be neck-and-neck coming into the final sprint. Not wanting to lose to each other, all manner of tripping, nut punches, and wrestling ensued. I don't remember who crossed the finish line first, but we did both get disqualified for unsportsmanlike conduct.
2. The other moment that comes to mind was playing coed soccer and facing an all-girls prep-school team. Naturally, we took this for an easy win, but went on to get our asses handed to us. They didn't just win, they played really dirty and beat the shit out of us.