There's a pretty simple way to get this, just requires luck.
While going for this you'll also work your way towards the achievement for winning 50 head to head matches.
Go into a head to head match with a buy-in of 100. Then, at your first possible chance, go all in and that forces the other player to either fold or go all in. If they continue to fold, you continue to win hands and can get the achievement for winning 5 consecutive hands.
So altogether you can get 3 achievements out of this, one for winning 50 head to head matches, one for knocking out 100 players in tourneys, and possibly one for winning 5 consecutive hands.
*If you win 5 head to head matches in a row, you will not get the achievement for winning 5 hands in a row as they are separate games and only count for one hand if you both go all-in; which is what happens 90% of the time.
You won't win everytime but to me it's a faster way to work towards multiple achievements at one time. You also gain tons of xp so you will level up a lot until about 20, then it starts to drag.
This is my first solution so please excuse the clutterness. I'll look over it and make adjustments once I learn the proper way to write a solution.