Mahan And Donaldson Play Each Others Balls... Which Is Wrong...

((HT: Golf Central Daily/BBC/USGA))

On a few different levels...

And it's a two-stroke penalty on the course...

On their 9th hole of the day (the 18th at Pinehurst No.2), Hunter Mahan played Jaime Donaldson's ball and vice versa. That is a two-stroke penalty for both golfers- regardless of intent- and both guys are having issues trying to make the cut at the US Open

Here's what you do next after you realize it...


Both double-bogeyed the hole...

Here's the rule in the books:

Rule 15-3:

If a competitor makes a stroke or strokes at a wrong ball, he incurs a penalty of two strokes.

The competitor must correct his mistake by playing the correct ball or by proceeding under the Rules. If he fails to correct his mistake before making a stroke on the next teeing ground or, in the case of the last hole of the round, fails to declare his intention to correct his mistake before leaving the putting green, he is disqualified.

Strokes made by a competitor with a wrong ball do not count in his score. If the wrong ball belongs to another competitor, its owner must place a ball on the spot from which the wrong ball was first played.

Exception: There is no penalty if a competitor makes a stroke at a wrong ball that is moving in water in a water hazard. Any strokes made at a wrong ball moving in water in a water hazard do not count in the competitor’s score.