If any of the lingo used below is unclear, please let me know and I will change it, but it does help to have a basic understanding of how the game is played to get this achievement.
Probably easiest to get in the "tournament" mode. The number of players and the buy-in amount don't really matter, but the _type_ of player does. Try to find one that plays "loose" and likes to call you out (ie, "Hakim"...I think that's his name at least...).
The big key to this cheevo is...YOU HAVE TO RAISE _BEFORE_ "THE FLOP", and then bet/raise every card after that.
Best to wait until you at least have two face cards...and it's even better if that "loose" player happens to be the "big blind" for that particular hand. Then, hope that you "flop" at least a pair and then push forward with bets/raises until the last card is dealt.
From experience, I have to say...DON'T GO "ALL IN"...it will probably scare off the other player(s) since the computer likes to fold. Hopefully the other player keeps calling and you can rope them in until "the showdown".
Beat them at the showdown and the achievement will pop. Good luck!