After a few years of playing online fairly frequently, I've finally won a tournament at the Button Men website. #9040, Match of the Day. OK, so it was a 8 person tourney, and I did win two of the matches by forfeit because the other player hadn't moved for 14 days, but it's still a win. The final match was my button, Cheese Weasel, versus the evil Pikathulhu. The first round was tense with us tying on points, but with some luck, I went on to win the next three matches. Hopefully, this win won't be my last.
(Technically, I won a tournament early in my playing career with a forfeit in the championship match, but a long-standing bug on the BM website has prevented that tournament from finishing, so it's never shown up on my record.)