"Taking On All Comers" Achievement Question

Taking On All Comers

Fight 10 opponents via fight requests.

Any ideas on how to unlock this achievement? I’ve tried inviting players to my games and have accepted invitations, both of these more than ten times and I still have this achievement locked.

Fight Request is not sending out game invites to other players, it is the feature where you can be challenged by an online player while you are playing Arcade Mode. Turn it on and sandbag against the CPU until someone challenges you.