can someone explain how to unlock this achievement?

Hey there everyone :)

i am in need of some friendly assitance. How exactly can i achieve the achievement known as Dishounoring foe?? I have the other two done i just need this one.

if you want to see my steam to verify here it is:

Sakura (pink picture)

Gamer girls ftw X3

Play a campaign against someone, give them 10,000 money and win the campaign? Kinda what it says in the description I guess.

tried that and it didn't work for me and my buddy :/

Suppose it is bugged then. I got quite a few of the multiplayer achievements without ever fighting an online battle =S