World number five Stephen Maguire suffered a shock 10-9 defeat by Dechawat Poomjaeng in the first round of the World Championship in Sheffield.
Poomjaeng, ranked 70, claimed a famous victory on his Crucible debut, ousting the number six seed.
Maguire, from Scotland, missed a chance in the deciding frame before Poomjaeng made a break of 63.
Ali Carter set up a second-round meeting against Ronnie O'Sullivan with a 10-4 win over Ben Woollaston.
Poomjaeng - only the third Thai to play in the tournament after James Wattana and Tai Pichit - was immediately embraced by the crowd for his antics, missing the entrance into the arena before walking towards the wrong table.
His exaggerated facial expressions and the applauding of his own safety shot were enjoyed by the crowd, while his excellent tactical game left Maguire frustrated.
Marco Fu and Ding Junhui took comfortable leads in the first session of their first round match against Matthew Stevens and Alan McManus at the snooker world championships being played in Sheffield.
Stephen Maguire is on the verge of an upset elimination by Dechawat Poomjaeng, who is leading 9-9 in a match that will resume this evening after the two matches on schedule.
Matthew Stevens (Wal) 3-6 Marco Fu (HK)
35-68, 19-58, 0-70 (70), 83-8 (83), 22-70 (62), 32-102 (71), 60-53, 74-8 (74), 7-62
Ding Junhui (Chn) 7-2 Alan McManus (Sco)
10-63, 131-1 (131), 10-101, 100-15 (67), 92-1 (61), 129-0 (129), 74-5 (51), 64-53, 86-46 (81)
Judd Trump (Eng) 6-3 Dominic Dale (Wal)
55-61 (60), 88-0 (88), 60-34, 33-68, 86-18, 142-0 (142), 105-13 (82), 86-0 (50), 48-64 (53)
Mark Selby (Eng) 6-3 Matthew Selt (Eng)
65-1, 61-46, 63-23, 76-7, 72-15, 10-103 (87), 67-54, 56-77 (57)
Ali Carter (Eng) 10-4 Ben Woollaston (Eng)
81-38, 54-85, 9-71, 30-91 (91), 84-0 (84), 64-50, 5-72 (72), 96-0 (96), 70-31 (52), 110-0 (106), 51-36, 65-54, 71-16, 62-60
Stephen Maguire (Sco) 9-10 Dechawat Poomjaeng (Tha)
0-79 (72), 2-102 (59), 99-32 (69), 45-86 (60), 12-81 (50), (Maguire 63, Poomjaeng 56), 40-57, 71-10, 77-4 (70), 116-0 (91), 98-32 (93), 44-80 (74), 8-81, 62-26, 21-72, 73-14, 0-68 (54), 61-45, 1-104 (63)