I agree with the previous posters -- all your betting was weak here. Raise more preflop and bet out on the flop (I always raise to 4x the big blind). You really have to put your opponent on a hand. What did you think he had? One reason to make larger bets is to get information about how much he likes his hand (or just doesn't think you have it this time....). It seems like this yahoo might have gone to the felt with AJ even if you bet out. If you put him on a lower ace and knew a super-weak lead on the turn (.50?!) would induce his hilarious bluff on the river, then this was a brilliant play. But you have to know all that stuff for it to be good, and without a great read that information comes from preflop and flop betting. Playing AJ like this is a huge mistake made by weak players, and is an ideal matchup for AK. You lucked out and he did your betting for you, but if you played this 100 times I think pot-sized flop bet and 2/3 or even push on the turn is a better line.