Lucas Bjerregaard was playing unspectacularly through eight holes Thursday at the U.S. Open. However, he was only 3 over as he stepped on the tee at Pebble Beach's par-5 18th hole, his ninth hole of the day.

That's when disaster struck.

Bjerregaard made a sextuple-bogey-11 to plummet down the leaderboard at 9 over.

The 11 still isn't anywhere close to the highest single-hole score in U.S. Open history. That unfortunate feat belongs to Ray Ainsley, who carded a 19 on the par-4 16th hole at Cherry Hills in 1938.