Hotly tipped Michael White made the Crucible debut of his dreams as he sent his hero and fellow Welshman Mark Williams home in the first round.
The Neath potter did so in style by turning a 5-4 overnight lead into a 10-6 victory. Meanwhile, four-time champion John Higgins was in trouble against Mark Davis, with the Scot letting an early 2-0 lead slip away as he fell 6-3 behind.
Earlier, Chester's Ricky Walden tied up a 10-1 victory over Nottingham's Michael Holt, earning his first World Championship win at the third attempt. Graeme Dott built a 6-2 lead over Peter Ebdon in an often-gruelling battle between former world champions that progressed at such a pedestrian pace they could not fit in the session's scheduled ninth frame. They resume this morning when, time permitting, they will play to a finish.
Stephen Hendry, the seven-times world champion, believes Ronnie O'Sullivan must knuckle down to stand any chance of eclipsing his impressive record of world titles.
Hendry remains the most successful player on snooker's greatest stage but he knows O'Sullivan has the potential to win three more world crowns, having made his comeback after a 12-month break at this year's championship.
"If (Ronnie) has got ambitions to beat my record, he really needs to knuckle down. He just has to have one objective over the next few years. He has got the game, but whether he has got it in him to focus and dedicate his life, we will have to see," he said.
Defending champion O'Sullivan showed few signs of rustiness or nerves in a 10-4 first-round win over Scotland's Marcus Campbell as the four-time world champion took an early step towards joining an elite group of players who have won the crown five or more times.
Only Hendry and Steve Davis, who have six world crowns, have won more titles than O'Sullivan at the Crucible, while Ray Reardon is the only other player to have won six titles.
Meanwhile, Barry Hearn, the World Snooker chairman, has lodged a complaint with the BBC after they pulled the plug on coverage of O'Sullivan's first-round match just before it was due to finish. Rather than show the end of the match, BBC2 switched to a repeat of 'Some Mothers Do 'Ave 'Em'.