How I beat an NM (in a simul... but still)

Today I played in a simul against NM alexsuper1987 of Italy. I completely lucked out and he played an opening which I had prepared for about 15 moves deep. It was a really interesting game, and after gaining a small advantage from the opening, I managed to grind out a win. The time control was 45|60, and I was playing black. I believe he had intended to play 20 or so opponents, but I don't think it ended up being quite that many. The game lasted about 2 and a half hours: the longest game I've ever played. He was far and away the highest rated player I've ever beaten. It was a lot of fun, and I'm sure I wouldn't be so lucky if a rematch was played :)