NL25 - Too aggressive with AK?

[jamez_kerry]

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

UTG ($20.90)
UTG+1 ($23.25)
MP1 ($10.15)
MP2 ($11.30)
CO ($15.90)
Hero ($23.75)
SB ($53.30)
BB ($19.25)

Preflop: Hero is Button with A[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#CC3333">UTG raises to $1</font>, <font color="#666666">3 folds</font>, CO calls $1, <font color="#CC3333">Hero raises to $3</font>, <font color="#666666">2 folds</font>, UTG calls $2, CO folds.

Flop: ($7.35) 7[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG bets $4.25</font>, <font color="#CC3333">Hero raises to $20.75</font>, UTG folds.

Final Pot: $32.35

So what do you think of this play? I think the raise on the button pf was good although not so sure about the all-in after the flop - maybe more of a tournament play than cash game? [img]/images/graemlins/confused.gif[/img] Plus it was my first hand I seen a flop with in the session so didn't really have a read on the guy yet.