NL25SH How to play the nuts on the River?

[stever1k]

PokerStars No-Limit Hold'em, $0.25 BB (4 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($24.75)
BB ($44.50)
UTG ($14.05)
Button ($32.75)

Preflop: Hero is SB with 4[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">UTG raises to $0.75</font>, Button calls $0.75, Hero calls $0.65, <font color="#666666">1 fold</font>.

Flop: ($2.50) 4[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">UTG bets $1</font>, Button folds, Hero calls $1.

Turn: ($4.50) Q[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $2.5</font>, UTG calls $2.50.

River: ($9.50) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $9.25</font>, UTG folds.

Final Pot: $9.50

Villain plays 54/35/2,86 for 50 hands. Reviewed, I wouldn't put him allin on the River, better try to get a decent bet called.
Turndonk... hmm I do not have to protect here, so I guess this donkbet was not the best line?