NL50: KQ Toppair vs river-raise

[Siracho]

hallo zusammen

No-Limit Hold'em, $0.50 BB (5 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

saw flop

Hero (SB) ($55.80)
BB ($27.50)
UTG ($50.70)
MP ($49.70)
Button ($69.70)

Preflop: Hero is SB with :qs, :kc
UTG bets $1.50, 2 folds, Hero calls $1.25, 1 fold

Flop: ($3.50) :qd, :3s, :7h (2 players)
Hero checks, UTG checks

Turn: ($3.50) :2s (2 players)
Hero bets $3, UTG calls $3

River: ($9.50) :4h (2 players)
Hero bets $6, UTG raises $15, Hero ??

villain komplett unknown

irgendwie macht villains line keinen sinn... ich war ratlos ob ich callen soll, vorallem da unknown... in solchen spots bin ich schon oft gegen geturntes oder gerivertes set gelaufen...