this is ~500 player multi-table tournment NL

there is a very lucky player who start to make allin bet at final 30 players, 20 players, final table and heads-up game

I am a chip leader for the whole game, and My work is need to sweep all the players out of the game, but he is very luck to call with ax vs my kk, kq vs my AQ and he is still stay alive.....

There is a headup game I played with that lucky player. I would like to use the skill of Dan Harrington and David...
But that player went all-in every hand.
The chip ration is about:
Me 120,000: 300,000 lucky player
Blind: 5k/10k

He went all-in every hand, Please give some advice how I play?

I got 89s and call his All-in bet vs his every hands allin play (A3)
and he won the championship....

is it my fault to call his allin with 89s?
Please give some comment, thx

KK_holdup