FT NL100: Flopped top set, get minraised, What's my line for max value

[QuietEarner]

I only have 9 hands with villain, did see him call a 3 bet with A7o and push a A34 all diamond flop (he had no diamond), he pushed the flop for his remaining 35BB he sat with approx 50BB. Oh yeah the A7o hand he cold called an UTG raise, then cold called the 3bet to close the action for heads up flop. Comes across as a complete donk.

Full Tilt No-Limit Hold'em, $1 BB (3 handed) Full Tilt Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($104.85)
Button ($103.10)
SB ($100.50)

Preflop: Hero is BB with 6[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/diamond.gif[/img].
<font color="#CC3333">Button raises to $2</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $7.5</font>, Button calls $4.50.

Flop: ($14.50) 5[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $9</font>, <font color="#CC3333">Button raises to $18</font>, <font color="#CC3333">Hero does what to maximize value?</font>