Below I have linked a video from a full match replay, where I earned this trophy at the end. If you don't have unlocked them already, you can also gain two other trophies in the same attempt.
Equip the "Scarab" or "Zippy" as the car of your choice and win the MVP trophy at the end of the match. Should come naturally (but I can not guarantee this)
Also, have the "Hearts" Decal equipped on your car.
And of course, to meet the requirements for this trophy you have to equip the "Shark Fin Topper" and then start an Exhibition match. Select "Unfair" as difficulty and then "1 VS 2" (should be default setting)
In general theory, the tactics is fairly simple. Shoot the first goal and just defend your own for the rest of the match. But, easier said then done, so...General tip: If you don't really need it, I also would recommend you, to disable the ball-cam temporary.
Like mentioned, right at the beginning of the match, instantly dash forward and shoot a goal after the first kick-off. If you can't make it, you might as well restart the match, but that's not a must if you are confient enough in your skills.
For the second kick-off, just kick away the ball from your own goal, then head back there and wait until the opponents try to shoot at it. In 8/10 attemps, the AI will try to shoot straight head-on. When this happens, just kick the ball as far away from your goal as even possible to gain some time.
If the opponent doesn't shoot head-on and the ball fly's in paralell to the boundary of the playing field you have to guess where it might bounce off to hit it and dispose it again. Also, always be on the lookout where both of the AI players are. You want to receive a goal because you lost track of one player.
If the ball does not fly into the opponents half of the playing field, JUST STAY INSIDE YOUR GOAL AND DON'T LOOSE SIGHT OF THE BALL!
If the ball and the opponents are far away and no immediate threat, use the momentum and refill your turbo boost. Best thing of course the full charge from the corners. Or the smaller recharge in front of the goal.
Also, if the ball is far away in the opponent half and you see a chance to get another goal yourself to extend the lead, you might use the opportunity. But always be aware, this tactic could backfire on you if you are not 100% vigilant.
Don't immediately give up if you receive a goal. Remember, the match runs 5 minutes. this can be a long time. And you always may get a chance to strike a fast counter-goal. In fact i would only advice you to restart, if you are behind more then one goal. Else, let the time run down and hope for a quick strike of your own.