World number one Ronnie O'Sullivan crashed out of the World Championship in the first round after suffering a stunning defeat to amateur James Cahill.
In arguably the biggest shock in the tournament's history, Cahill held his nerve to beat five-time champion O'Sullivan 10-8 at the Crucible.
O'Sullivan was a prohibitive favourite before the match after a season which saw him win five titles and compile his 1,000th career century on his way to victory in the Tour Championship.
But after recovering from 8-5 down to get back on level terms with the aid of breaks of 104 and 89, O'Sullivan missed a great chance to snatch the 17th frame and Cahill took advantage to move 9-8 in front.
O'Sullivan looked on course to set up a final-frame decider only to inadvertently pot a red when breaking the pack open from the blue, leaving Cahill to produce a nerveless break of 53.
The 23-year-old from Blackpool will face Scotland's Stephen Maguire in the second round.