$50 6-max, hit top pair on the river and suddenly face big bet

[Gavagai]

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

BB ($49.25)
UTG ($38)
MP ($65.50)
CO ($67.20)
Hero ($46.25)
SB ($10.80)

Preflop: Hero is Button with J/images/graemlins/spade.gif, A/images/graemlins/diamond.gif.
<font color="#666666">1 fold</font>, MP calls $0.50, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $2.5</font>, <font color="#666666">2 folds</font>, MP calls $2.

Flop: ($5.75) 8/images/graemlins/club.gif, 4/images/graemlins/spade.gif, 5/images/graemlins/spade.gif <font color="#0000FF">(2 players)</font>
MP checks, <font color="#CC3333">Hero bets $3</font>, MP calls $3.

Turn: ($11.75) K/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
MP checks, Hero checks.

River: ($11.75) A/images/graemlins/spade.gif <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP bets $8.5</font>

Should I call this?

Thanks,

Gavagai

[2PAUL2]

fold. i dont see a hand you beat that plays this way.

paul

[orange]

I usually bet the turn. Fold the river.

[Gavagai]

How would you decide whether this is a good spot to bet the turn? Surely one will often get called? And how much would you bet?

I do often fire a second barrell here, but I think it might be a leak, you lose quite alot when it doesn't work. In this case I didn't do so because this player was loose and would call big bets with weak pairs and draws.

[snowbank]

He hit his flush. Fold.

[Gavagai]

I folded and he showed pocket 2s