[mike l.]

so what i see this stuff all the time on 5-10 party heads up games. the river is perfect because the K and the board will freeze him up and he'll just call often with some better hands and always with A high. but i think you lost some value on earlier streets but not putting in more action with the likely winner. you couldve:

reraised preflop
let it go 3 bets on the flop
c/red and called the turn

i think you left a some chips in his stack on this one.