Not a solution but i can and will help people to boost this achievement, all we gotta do is load up a private match and the person who doesn't need the achievement quits out. Simples. :)
if you want to get this achievement without boosting all you have to do is go into a multiplayer game (if one still exists) and either beat the opponent or hope he leaves the game. If either one happens then you should receive your achievement for winning a game.