This is the same as the other online friendlies achievement except this one must be played in the 'Ultimate Team' mode.
Once in Ultimate team you must go to the online tab and in the bottom right hand corner you can use
to switch between 'Friendly Seasons' and 'Online single match'. You want the friendly seasons.
Now just invite your friend/boosting partner and have them quit out after you have kicked off. They must do this 3 times for you to be the champion and get your achievement.
Note: This will use up your players/managers contracts, so use your starter bronze players with loads of contracts on them if you wish.