Originally Posted by tim_speights
Only the host will actually be able to net the achievement. Also make sure that its an online game and that it is a challenge the other player doesn't have unlocked. The easy way to do it would be having your online counterpart use a second controller and sign in as guest. I unlocked the achievement after the second race.
I can confirm this. thanks for the hint.
Worked just fine for me, after 2nd minigame the achievement unlocked.
1st xbox: just me, no 2nd controller
2nd xbox: one account with just a few achievements and 2 guest profiles
Game Type: Player Match
Game Mode: Middle
Invite Only: 0