Simply start a Quick-Play Game against your 2nd controller.
Keep scoring with Player 1. If player 2 gets the ball, just throw up a half-court or full-court shot to turn the ball over. And keep scoring with player one.
You should be up much more than 10 points. The Achievement will pop at Halftime
You will also get the "Turning Point" Achievement for outscoring an opponent by 10 points in a single quarter
Here is a Video Guide: