NHL 08

You're running out of time for this one if you don't have it already, as the servers will close for this game on February 8th, 2011.

Play a Ranked Versus Game (accessed off the Xbox LIVE menu), and either legitimately or with a boosting partner, keep the score tied as the clock runs down in the third period. You'll have a five minute period of 4-on-4 hockey in which to score the decisive goal. You can have your opponent pull his goalie (LB + BACK) for the easy score if need be. Once the game is over, the Achievement will unlock.

Note that only the player who started the game (setting up the options using his controller) will earn the Achievement. Playing on the same team with another Gamertag will not award the Achievement to both players.