Final Table

I made a final table today in a $2 quintuple shootout. 1024 people enter and you play at tables of four someone wins and then you moved to the next round. I've probably played this event 15 times and never even cashed until today. To cash, you have to win two rounds. I won my first four tables, and was really playing well. In the final four I 3 bet all in with KK and a donk calls with AK - he hits an ace on the flop and I'm out in fourth place for $81. Not bad, but I would have won the whole thing if I won that hand.