PokerStars No-Limit Hold'em Tourney, Big Blind is t50 (9 handed) converter

SB (t1255)
Hero (t4550)
UTG (t1315)
UTG+1 (t1670)
MP1 (t1575)
MP2 (t2325)
MP3 (t700)
CO (t3375)
Button (t3495)

Preflop: Hero is BB with Th, Ah.
1 fold, UTG+1 calls t50, 2 folds, MP3 calls t50, 3 folds, Hero checks.

Flop: (t175) Ad, Tc, 7h (3 players)
Hero bets t100, UTG+1 calls t100, MP3 raises to t650, Hero raises to t1650, UTG+1 calls t1520 (All-In).

Turn: (t4095) Qh (3 players, 1 all-in)

River: (t4095) 3s (3 players, 1 all-in)

Final Pot: t4095

Based on the action would you have folded this? I just felt like top 2 on a relatively uncoordinated flop was pretty solid but it cost me plenty to find out it wasn't.

to be honest, it depends on how much the tourney buyin was. in a five or ten dollar tournament, i call this every time. more often than not, you're up against AK or even some garbage like A2. at these buyins, the set just cold calls you here and tries to extract on the turn. almost every time.

in a higher buyin tournament, like 50-300 dollars, i would probably fold.

for what it's worth, i think you're losing to a set of 7s here, since you're posting the hand, but i think you made a good call for the low buyin tourneys.

no preflop raise in a multi way pot with aces= bad play

You think I should have raised AT out of the BB there?

I think u played the hand fine. Some hands ur just due to lose with. I don't see how u can put the utg on 77. Especially since that mp raises so much. Ur forced to reraise here. Even if u called and the utg went allin I don't see u folding as a set is all that beats u and u still have 2 cards to fill up. Considering ur stacksize compared to utg this is standard. Only thing i see wrong is maybe the lead out for 100. There's no way ur laying this hand down on the flop tho considering ur opponents.