Ronnie O'Sullivan served up a reminder of why the Betfred.com World Championship needs him around as he twice threatened to plunder a maximum 147 break in his Crucible opener.
Eleven days ago, the three-time champion informed organisers he had decided to pull out of the tournament, only to reverse his decision 24 hours later.
At times today he played kamikaze snooker, taking on shots which were laced with danger, but mostly the three-time champion was brilliant as he developed a 7-2 lead over Dominic Dale.
In the process he made his 100th century at the Betfred.com World Championship, a 113 break in the eighth frame.
But it was the runs he went on in the second and seventh frames which threatened to bring the packed crowd to its feet.
He rattled in eight reds and blacks in the second frame, but luck deserted the 35-year-old off the ninth red. He sent the white through baulk and back before it flicked a middle knuckle. The black was unavailable, and O'Sullivan finished on 78.
The second opportunity looked certain to bring about O'Sullivan's 11th career 147, and his fourth at the Crucible. The balls could hardly have been more ideally placed, but after reaching 96 he ran slightly out of position and jarred the 13th red in the far corner, the ball wriggling away from the pocket.
While in previous years a maximum would have been worth £157,000, this year there is only a £10,000 high-break prize on offer, with the bonus for a 147 having been scrapped in a cost-saving move.
The presence of O'Sullivan had brought a buzz to the Crucible. This year, however, the anticipation was generated more by the warning he might stay away than by any semblance of form.
Four successive first-round exits from major tournaments have sent O'Sullivan sliding to 10th in the world rankings, and led to renewed speculation about his future in the sport.
World Snooker chief Barry Hearn was in the building today, and was thankful the sport's most exhilarating talent had joined him.
‘I'd miss Ronnie. I want to see the real Ronnie. He's special, he's a special person,’ Hearn said.
‘I love the boy to death. He's a fabulous snooker player. Rather than people say to me 'Do you have a problem with Ronnie O'Sullivan?'. I wish I had 10 Ronnie O'Sullivans.’
But Hearn was as unsure as anyone about what to expect from the sport's most charismatic character, who was watched today, as he often is, by the artist Damien Hirst.
‘I don't know what Ronnie O'Sullivan is going to do and I'm not sure Ronnie O'Sullivan knows what Ronnie O'Sullivan is going to do,’ Hearn said.
‘Did he think about pulling out? Yeah, I think so. But he's here and he's playing and I welcome him.’
O'Sullivan's first-round opponent was an entirely different sort of character, with Vienna-based Welshman Dale renowned as a joker of the tour.
World number 33 Dale, despite being troubled by the match commentary which was audible in the arena, was on level terms at 2-2 by the mid-session interval thanks to breaks of 47 and 56 and opportunities squandered by O'Sullivan.
But the plot soon changed, with O'Sullivan following his second maximum close call with a landmark ton and a 73 break to bring an end to the session.
Stephen Hendry held his nerve to win a final-frame decider for the second successive year.
The 42-year-old edged past Zhang Anda in 2010 and today beat Joe Perry 10-9 in a tense finish.
Hendry headed into the match knowing that defeat would knock him out of the top 16 for the first time since 1988.
The prospect of that and therefore having to play qualifying rounds for the ranking events, has never appealed to the seven-time world champion.
He led 6-3 after the opening session but that advantage was wiped out after Perry won the first three frames this afternoon.
Hendry edged ahead with a 67 break, but Perry came back to 7-7 with an 80.
Hendry inched 8-7 and 9-8 in front, but Perry kept coming back at him.
At 53-1 up in the decider, Hendry seemed home and dry. Perry came back to 53-34, but missed a critical brown and got no closer.