Zach Johnson knocks ball off tee with practice swing at the Masters

Patton Kizzire hits from the fourth hole during the second round for the Masters golf tournament Friday

Watch: Zach Johnson Accidentally Hits Ball on Practice Swing at the Masters

In his 15 years at the Masters, in his two decades as a pro, Zach Johnson had never experienced a shot like this. If the mishap had happened on his second shot from the middle of the fairway, after he'd already hit his tee shot, he would have had to replace his ball in its original position and incur a one-stroke penalty.

His ball cannoned off the tee marker and ran onto the next tee with Johnson walking anxiously after it, although he then turned to enquire with his playing partners whether he was allowed to re-tee it, before he picked it up.

"Y'all can laugh. That's embarrassing", he said taking another practice swing.

Johnson was so stunned he blurted out, "Oh, (s--)" before turning to his group to figure out his next move. "I thought I'd done it all, but now I know I have", said the 43-year-old, who added Kuchar would not let him forget the gaffe. "I don't think I could do it again if I tried".

Zach Johnson of the United States plays his shot from the eighth tee during the second round of the Masters at Augusta National Golf Club on April 12, 2019 in Augusta, Georgia.

Luckily for Johnson, the rules actually helped him on this one, and Johnson knew the rule immediately.

Johnson drilled his tee shot and wound up making birdie on his way to a 73.

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