Who is the highest-rated opponent you've ever played, and how did the game go?

Good forum post , I versed an FM in a daily game and managed to actually win. He missed a game-winning fork in the middlegame but I'll still say that it's my highest-rated win.

Nice! Thank you for sharing!

a 669 player in a rated rapid match!

https://www.chess.com/live/game/129055422945

this brought me to 300 rapid :0

Played an FM who is 2900 chess.com blitz, we went into a mainline caro kann but he made a mistake and i had a winning attack which I messed up back to equality, and then I blundered my queen. I was actually so mad

I played against my coach , 2100 fide and I lost miserably

My highest rated victory is against a 1530 player I think

I played an IM with a rating of 2500 from the Netherlands in unrated blitz, and I ended up finding a brilliant bishop sacrifice and ending up winning by checkmate later!

I had the opportunity to play a several titled players on Chess 24 a few years ago when they did Banter Blitz . I got to play Ding Liren in a 8 person simul also. He was #3 in the world at the time. My favorite moment was when I decided to play a quick 3 min blitz before bed one night and ended up randomly getting a game with Jan Gustafsson. I didn't surprise anyone but thoroughly enjoyed playing them all.

Played my coach who’s 2500 blitz and actually held up but blundered a mate

Nice! Here is possible to play against Titled players(Many GM/WGM): https://boltchess.com/

I played an IM, he was Irish which is unusual I think, didn't disgrace myself and he won on time

Tal.

In a simul, in 1988 in Saint John.

We drew.

He was just lucky.