Reckless Racing Ultimate

Definitely you will need to boost here since I could not get any games in quick match.

So what you will need to do is:
1) Reserve a time with your boosting partner and them create several duels with him.
2) You should create 10 in the shorty circuit with 5 minutes limit.
3) Then took turns winning, so each one has 5 (make easy times to beat, like 35 for the lap). Host can only play after guest accepts duel.
4) Then wait in the lobby, it will update the progress by showing the time remaining. When your five winning duels finish, you will get the achievement.

Important: You should not forfeit a duel. IT WILL NOT COUNT. However, sometimes the duels can freeze (time stops or score does not update), and I think it is better to forfeit and try another one.

You can see the ones that really counted, on the finished section of the duel window. If it has a time in green in it, then it counted.

UPDATE: You can also see how many duel you have by clicking on your gamerpicture on the home screen of the game.

Happy boosting.