Lesson of the day: Don't bet against Maurice Edu.

Subsequent lesson of the day: Especially don't wager a full-blown slap to the face from Edu.

Unfortunately for him Fortunately for us, KICKTV’s Billy Keenly had to learn that lesson the hard way.

This brilliant soul told the Philadelphia Union midfielder that he couldn't reach a score of 10 on the popular mobile game "Flappy Bird." He also told Edu that if he did so, he could slap him across the face.

Well, Edu hit a score of 10 with relative ease, and then he hit his hater with a swift right hand.

Let's roll that beautiful #SmackCam footage.