PokerStars 3/6 Hold'em (10 handed)

Preflop: Hero is UTG+2 with , .
1 fold, UTG+1 calls, Hero calls, MP1 raises, MP2 calls, MP3 calls, 2 folds, SB calls, BB calls, UTG+1 calls, Hero calls.

Flop: (14 SB) , , (7 players)
SB checks, BB bets, UTG+1 calls, Hero calls, MP1 folds, MP2 calls, MP3 folds, SB calls.

Turn: (9.50 BB) (5 players)
SB checks, BB bets, UTG+1 calls, Hero raises, MP2 folds, SB folds, BB calls, UTG+1 calls.

River: (15.50 BB) (3 players)
BB bets, UTG+1 calls, Hero raises, BB calls, UTG+1 calls.

Final Pot: 21.50 BB

Results in white below:
BB has Js 5s (flush, ace high).
UTG+1 has Tc 9c (two pair, tens and nines).
Hero has Ac 8s (straight, ten high).
Outcome: BB wins 21.50 BB.

With top pair and an open ender on the turn....I lose a HUGE pot.

welcome to poker.