Comeback Kid Achievement in FIFA 12
Win after being down 3 goals in the 2nd half in a game vs. the CPU
How to unlock Comeback Kid
You'll want to do this one along with 10 vs 11. Change the settings for your team only like you did for Legendary, and set the time on long enough to make sure you can get a red card. Start the match and make sure you get a red card. When you get it, make 3 own goals and let the 1st half finish. Then, in the second half, score at least 4 goals and win the game.