Neither player realized the error until they reached the green. The penalty for playing the wrong ball is two shots, so the players had to return to the spot where they hit the incorrect golf balls and play from the correct spot.

Under Rule 6.3c, it’s a two-shot penalty for each player who hit the wrong ball, and the mistake must be corrected by going back and playing the correct ball to finish the hole. Both Zalatoris and Davis did. Both made bogey when both would’ve made birdie.