World number one Ronnie O'Sullivan was knocked out of the World Championships by the first ever amateur to qualify for the tournament, James Cahill, in the first round.
Ronnie O'Sullivan lost in the first round of the World Championships 10-8 to James Cahill with the five time champion looking tired and sloppy throughout two days of the match.
O'Sullivan's form this season, in winning the Players Championship and Tour Championship, had taken him back to the top of the world rankings and made him favourite for the World Championships.
The 43 year old is in one of the hottest periods of his career but hasn't been the world champion since 2013, only reaching the final once since, and was expected to change that this year.
His first round opponent was James Cahill. The 23 year old had become the first ever amateur to qualify for the worlds when he beat fellow amateur Michael Judge in the qualifiers.
Cahill had turned professional in 2013, aged just 17, and remained professional until 2017 when he was knocked out of the first round of the Q School tournament.
Last year he defeated then world number one Mark Selby in the first round of the UK Championships and then progressed in Q School to earn his place back in the tour for the 2019/20 and 20/21 seasons.
He was still amateur going into the World Championships and was handed the daunting task of facing O'Sullivan in the first round.
Very much sums up O'Sullivan's day. Image: PA Images
'The King's Nephew,' a nickname from being Stephen Hendry's nephew, kept exchanging frames with his more illustrious opponent in the first session on Easter Monday and led 5-4 after the first day.
Ronnie had been sloppy on day one but was expected to come back stronger on the second day. However the younger man was still on form and took an 8-5 lead.
O'Sullivan suddenly seemed to click into gear though as he took the next three frames, including breaks of 102 and 89, to make it 8-8.
A break of 53 made it look like the 43 year old would take the lead and 9-8 and end the resistance of the amateur but he made another mistake, potting a red whilst on the blue, and with a bunch of split reds Cahill cleaned up to put himself within one of the win.
Cahill showed no nerves in the 18th frame of the match and his break of 53 gave him the win and possibly the biggest upset in the history of the tournament. He next faces Stephen Maguire after the Scot won 10-9 against Tian Pengfei.