This description is actually wrong - this isn't for winning an entire match, it's for scoring 1 point (out of at least 8) in a match. You will get this in your first multiplayer match, whether it's local or online. Boosted in about 2 seconds with a friend.
Tips pasted from the solution for "No one can beat me!":
Just have your friend (or second controller) drive off the cliff immediately after starting. The Ice Bridge level allows you to suicide right away.
You can change the match settings to make it as short as possible (which is 8 points to win, i.e. 8 suicides for the losing player), and you can make it a private match with no public slots. Repeat 10 times for the achievement. Takes about 5 minutes.