HELP !!!! How do people call this ????

[Trappped]

Two tourneys back to back where I flopped top pair with JT suited and got called down with AK and both donkeys hit the turn.
The first time occured in the Stars $3 rebuy after the rebuy period.
Was down to 1600, blinds 100/200, I limp UTG with QJ of dia.
Button (has over 10k in chips) raises to 800, I call. Jack hit the flop, 8 9 J of hearts to be exact. I'm 1st to act postflop, bet my last 800, guy calls with AK os, black. King hits the turn, Ok, not enough chips to protect my hand, $3 tourney, yadda yadda, I can swallow this one.
The second one is the Killer. Full tilt, $163 buy in nightly $35k (pot was over 50k ), blinds up to 100/200, about 160 left out of 378, I'm in the BB with JT of clubs, with 5k in my stack. UTG raises to 600, he has me covered, maybe 8k. Everyone folds, I call, I'm HU and 1st to act.
Pot is 1300, J89 flop, non suited in red, I push all in for 4400 (1st to act) figuring that I can bluff the straight or draw out if I'm behind with a J,T, 7, or Q. The dude INSTACALLS with AK of clubs and turns a King, river is a blank and I lose.
How the hell does he make this call ??
Seriously ??