The first thing you need for this achievement is the Hearts Decal pattern. This will be one of the many rewards for completing a match. You can quickly collect items by starting an Exhibition match with no bots and set scoring limit to 1. Not all designs are available for every car. At this time, only Zippy and Scarab can get the Hearts decal.
Now that you have hearts equipped from the garage, start an Exhibition match with these settings.
-All-Star Bot difficulty
Mutator settings should be default with this change:
-Score maximum 1
Using 2v2 you have a teammate on the same level as the opponents without making it too difficult to score. If the other team scores simply restart and try again. Just play smart and try to take advantage of shots near the goal. Be ready to play defensive even though your teammate does a good job of it. With some luck, your teammate may even make the goal for you which will still unlock the achievement. Good luck, and I hope this helps.
NOTE: If you meet the requirements and this doesn't unlock double check that you are connected to the Rocket League servers. If you're not, then try to get them back on by starting an online match then try again.