Glasgow - Ronnie O'Sullivan racked up a 147 break on Monday before revealing he had to be "guilt-tripped" into potting the final black after discovering there was no bonus prize for a maximum.
Having sunk the pink to reach 140, the 34-year-old left the table to shake hands with opponent Mark King after wrapping up a 3-0 win at the World Open.
However referee Jan Verhaas intervened to urge O'Sullivan to complete his maximum for the benefit of watching fans, the player revealed.
"I wasn't going to pot the black because to make 147 and not really get a nice bonus was a bit disappointing because they are magical moments and they deserve magical bonuses," O'Sullivan said.
"But the ref played a guilt trip on me and said 'Come on, do it for your fans`. And I thought, 'Okay, because I haven`t got long to play anyway, so I might as well go out on a high.'"
Instead of a "magical" bonus, O'Sullivan had to be content in the knowledge that he is likely to win the £4 000 prize for highest break of the tournament.
The world number six claimed scoring a 140 break would have given him just as much satisfaction as the 10th maximum of his career.
"I got as much a kick out of doing that as I would have done making it," he added. "It's a great achievement to make a 140 and not pot the black. It shows that to me they are not that difficult to make."