Thepchaiya Un-Nooh suffered the heartbreak of missing the final black for a maximum 147 break for the second time this season.
The Thai had missed a black off the spot at the UK Championship in December, and was left further frustrated in his World Championship qualifier against Anthony McGill on Tuesday.
Thepchaiya left himself slightly low on the final black, also off the spot, with the ball rattling in the jaws of the bottom-left pocket before bouncing out, causing the Thai to throw his cue onto the table in frustration.
The error cost Thepchaiya an £8,500 bonus, although he looks in good shape to claim the £1,000 prize for the highest break in qualifying, as he recovered his composure remarkably to knock in a 144 in frame eight, bettering the 142 made by Peter Lines.