NLCASH $10 pair and overcard A on the flop

[Triggerle]

This was a hand fairly early in our HU match. Villian seemed quite aggressive but, unlike most NL10 HU cash players, at least somewhat decent.

Is my raise on the flop too aggressive? Should I fold with a pair and an A?

(This is one of my first HU sessions ever and also my first post in this forum.)

EverestPoker Game #1609631058: Table Tirana-16 - $0.05/$0.10 - No Limit Hold'em - 23:41:35 - 2007/06/01
Seat 1: Hero ($11.35)
Seat 2: Villian ($12.50)

*** HOLE CARDS ***
Dealt to Hero (Button) [4[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/diamond.gif[/img]]
<font color="red">Hero raises to $0.35</font>, <font color="red">Villian raises to $1.05</font>, Hero calls $0.70.

*** FLOP *** ($2.10) [7[img]/images/graemlins/diamond.gif[/img] 4[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/spade.gif[/img]]
<font color="red">Villian bets $1.70</font>, <font color="red">Hero raises to $5.00</font>, <font color="red">Villian raises to $11.45</font> and is all-in, Hero calls $5.30 and is all-in.