This isn't a solid guide YET for how to obtain, but I do have these pointers I've learned for for those of us that only have one Xbox.
1. You cannot do this solo you must be partnered in a 2v2 tournament at least.
2. Setup tournaments yourself and in Requirements limit the highest level to your level. That way you are playing against people your level or lower. Otherwise you'll have a pro join and wipe you. (I'm Silver 1 in 2v2 and 3v3 currently and playing a Platinum would just be painful.)
3. You still have to not only win the game AND be the best player on the team, but if you get someone to partner up with you that is about your skill level you have good odds. OR if your buddy can try to setup shots for you by centering the ball for you to take the shot. If you happen to have the lead, your buddy can score so long as they don't out score/perform you.
Either have 1 friend and both of you have a 2nd controller, OR get 3 friends together and setup a private tournament and then you can see who is best for the first round and then next round help whoever still needs the achievement.
Hope these tips are helpful. Still working on this one myself....and now I started reading through the comments on the other solution and saw a lot of what I posted above. Still Going to leave it out here because not everyone reads through all the comments.