Autocall with this overpair???

[Shes92]

Poker Stars
No Limit Holdem Tournament
Blinds: t75/t150
8 players
Converter

Stack sizes:
UTG: t2900
UTG+1: t5535
MP1: t1180
MP2: t5300
CO: t3375
Button: t12090
SB: t5695
Hero: t5190

Pre-flop: (8 players) Hero is BB with J[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/diamond.gif[/img]
UTG calls t150 <font color="aaaaaa">(pot was t225)</font>, UTG+1 calls t150 <font color="aaaaaa">(pot was t375)</font>, 4 folds, SB calls t75 <font color="aaaaaa">(pot was t525)</font>, <font color="#cc0000">Hero raises to t800</font>, UTG folds, UTG+1 calls t650 <font color="aaaaaa">(pot was t1250)</font>, SB folds.

Flop: 6[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/spade.gif[/img] (t1900, 2 players)
Hero bets t1900, UTG+1 raises to t3800, Hero ??

Is this a definite call? My thoughts were that he had hit a set but couldnt be confident due to the fact that Ive only been at the table for less than 2 rounds so no reads and its a 4/180 where players are liable to bluff at this with AX.