China's Ding Junhui was left red-faced after throwing away the chance of a maximum 147 break and the £30,000 prize that goes with it at the Betfred World Championship on Tuesday.
Ding potted 12 reds and 12 blacks to rack up 96 points but after knocking in the 13th red he screwed back up the table to get position on the blue.
The world No 3 suddenly realised what he had done and held his head in his hands before starting to giggle along with his first-round opponent Mark Davis.
He composed himself before attempting a very difficult cut on the black but was unable to keep the break going when his shot missed.
Had he not suffered such a bizarre lapse of concentration, Ding may have added his name to the exclusive list of players to achieve the feat at the Crucible.
Indeed, it has only been accomplished on 10 previous occasions at the renowned Sheffield venue.
Ding, who went on to win the match 10-7, admitted he did not realise he had been on course for a maximum break until the crowd gasped after the shot which put him on the blue.
“I just kept scoring and trying to make centuries and heavier breaks and put him under pressure…until the last red I potted and then I heard the noises and looked at the scoreboard. I tried to make it difficult for myself, and that's it!” he said.
"I just make centuries. I didn't know, really. I didn't even think about playing for a 147 but to keep going and keep potting the balls."
Ding will play John Higgins in the next round, and added: "I've played him many, many times. I've learned a lot from him. I've got more confidence to play him now."