PokerStars, Hold'em No Limit - 50/100 - 9 players
Hand delivered by Upswing Poker

alessandr436 (UTG): 1,802 (18 bb)
quix954 (UTG+1): 2,925 (29 bb)
Rosxana13 (MP): 2,660 (27 bb)
Bambini7777 (MP+1): 3,753 (38 bb)
Ananke222 (LP): 1,432 (14 bb)
Fortzon (CO): 1,195 (12 bb)
TudorPithon (BU): 1,529 (15 bb)
alaercio (SB): 2,961 (30 bb)
ar6timchap (BB): 1,405 (14 bb)

Pre-Flop: (150) Hero (alaercio) is SB with 7♦ 7♣
alessandr436 (UTG) calls 100, quix954 (UTG+1) calls 100, 1 fold, Bambini7777 (MP+1) raises to 300, 3 players fold, alaercio (SB) calls 250, 1 fold, alessandr436 (UTG) calls 200, 1 fold

Flop: (1,100) 4♥ 7♠ 9♠ (3 players)
alaercio (SB) checks, alessandr436 (UTG) checks, Bambini7777 (MP+1) bets 737, alaercio (SB) raises to 2,661 (all-in), alessandr436 (UTG) folds, Bambini7777 (MP+1) calls 1,924

Turn: (6,422) T♠ (2 players, 1 all-in)

River: (6,422) J♣ (2 players, 1 all-in)

Total pot: 6,422

Showdown:
alaercio (SB) shows 7♦ 7♣ (three of a kind, Sevens)
(http://www.propokertools.com/simulations/unrolled?g=he&s=generic&b=4h7s9sTsJc&h1=TdTh&h2=7d7c - Pre-Flop: 19%, Flop: 88%, Turn: 2%, River: 0%)

Bambini7777 (MP+1) shows T♦ T♥ (three of a kind, Tens)
(http://www.propokertools.com/simulations/unrolled?g=he&s=generic&b=4h7s9sTsJc&h1=TdTh&h2=7d7c - Pre-Flop: 81%, Flop: 12%, Turn: 98%, River: 100%)

Bambini7777 (MP+1) wins 6,422

I would have played it the same way.

It was a set over a set. Nearly all of the time, the lower set loses their entire stack. There's nothing much you can do about that.

Doyle Brunson said never fold a set