I keep trying to think of something more recent that was more surprising but I keep coming back to this one, season VIII vs. dreuj:
http://warlight.net/MultiPlayer?GameID=3963978 After turn 3 I was certain I had lost before the miracle turn 4. And then I kept expecting to fail to defend West Russia from Caucasus, but nope, I predicted every single important move. Freaking surreal.
Of course dreuj had absolutely no problem kicking my ass since then, 0-2 in 1v1 and 0-2 in 2v2 :P
Some other surprising results include going 4-1 against apex (losing against x) in a guiroma RR, and and beating Timinator on the 1v1 ladder while losing to practically everyone else.