In order to get this Achievement, you will have to win the Online FIFA World Cup with a team rated 1.5 or 2 stars.
In the Main Menu, select "Online FIFA World Cup" and select a 2 star rated team.
For all teams rated with 2 stars check "Two Star Group Stage" above.
The same principle as above applies for this Achievement.
Quit out of every match until you find a team that you can beat. With some skill, you can beat teams rated 3 stars; more skilled players will even be able to beat teams rated 3.5 or 4, but don't underestimate the difference between teams.
The safe way is to just wait until you find a team rated 2 or 3 and to go for it.