Stars $22 180 man MTT, heads up A7

PokerStars No-Limit Hold'em Tourney, Big Blind is t8000 (2 handed) FTR converter on zerodivide.cx

Button (t127918)
Hero (t142082)

Preflop: Hero is BB with A[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/club.gif[/img].
Button raises to t16000, Hero calls t8000.

Flop: (t24400) 6[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/diamond.gif[/img] (2 players)
Hero checks, Button bets t14000, Hero calls t14000.

Turn: (t52400) 8[img]/images/graemlins/spade.gif[/img] (2 players)
Hero checks, Button bets t20000, Hero calls t20000.

River: (t92400) T[img]/images/graemlins/heart.gif[/img] (2 players)
Hero checks, Button bets t45000, Hero ?.


I think my line could use some improvement. What line would you use? What do you put my opponent on?


Some background: This is exactly the 19th hand of heads up. He raised from sb to 18k on the 1st and 3rd hands of heads up (3/6k blinds). This was the first time, since then, that he had raised. Villain had only made multiple street bets once in our heads up history. I completed w/ 48o (3/6k blinds) from sb, on a 6[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/heart.gif[/img] board, flop: check, check, turn: bet 8k, call 8k, river: bet 14k, call 14k, Villain showed Q5o.