Protecting a marginal hand in SB

[J. Stew]

Party Poker 0.50/1 Hold'em (9 handed) converter

Preflop: Hero is SB with T[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#666666">1 fold</font>, MP2 calls, <font color="#666666">1 fold</font>, CO calls, <font color="#666666">1 fold</font>, Hero completes, BB checks.

I don't normally complete with unsuited 910 but I read something about the value of this hand with three to four players, don't know if its applicable at this level though.

Flop: (5 SB) 9[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/diamond.gif[/img], 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets</font>, BB folds, UTG+1 calls, MP2 calls, CO calls.

I wasn't expecting a bet from a late position player but it obviously could have come. Would you check-raise to protect this hand or just lead out and see what happens?

Turn: (4.50 BB) 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, UTG+1 calls, MP2 calls, CO calls.

The players were pretty standard loose/passive, especially utg+1, I bet cause I thought I had the best hand.

River: (8.50 BB) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, UTG+1 calls, MP2 folds, CO folds.

Standard river bet I think, I would have liked to narrow down the field on the flop though. I posted a hand about a week ago where I was in a similar position but with a non-overcard kicker and the consesus was to lead out. I think that argument's even stronger with an overcard kicker, but what's a better strategy for this hand on the flop, to lead out with what might be the best hand or to check-raise and try to knock players out?
Final Pot: 10.50 BB