Who has beaten a chess master before? (CM IM, GM, etc.)

The only way I will be able to beat one :/

A lot of them in variants but only one in ultra

I beat a nm on chess.com

I drew with a titled player at blitz. Was winning at one point too, but couldn't complete it. Still I was quite satisfied with a draw.
I beat one at Fog Of War, and could probably beat many of them at anti-chess too, but you can't really count those.

A few times but that's my best so far:

I have to admit though: We were having some drinks that day.

Probably most players managed to do that at one point or another.