Judd Trump fell victim to one of the biggest shocks in Crucible history as he crashed out of the Betfred World Championship to rank outsider Rory McLeod.
The world No 2, joint-favourite for the trophy alongside reigning champion Mark Selby, was beaten 10-8 by the 46-year-old qualifier in a first-round match which spanned three sessions.
Trump, who won the opening four frames on Tuesday but trailed 5-4 overnight, continued to struggle on Wednesday and found himself one frame away from defeat at 9-7 when play was halted until the evening.
McLeod, priced at 1,000/1 to win the title by some bookmakers at the start of the tournament, then took two frames to finish the job and set up a second-round meeting with Stephen Maguire.
Trump, runner-up in 2011, failed to find his rhythm against the world number 54 and was guilty of some poor positional play and wild potting attempts.
There was some suggestion he was struggling with an injury during the match, and he had plenty to feel uncomfortable about as McLeod sent him home early with a memorable victory, which was wrapped up by tense 18th frame.
After the defeat Trump refused to do a post-match press conference.
There were also upsets in the other two matches completed on Wednesday as Graeme Dott and China's Xiao Guodong joined McLeod in the last 16.
Breaking - Judd Trump has refused to do mandatory press conference. He'll be disciplined for breach of contract #bbcsnooker
— George Riley �� (@georgeyboy) April 19, 2017
Dott, the 2006 champion, overcame two-time finalist Ali Carter, while Xiao knocked out world number 16 Ryan Day.
Scotsman Dott, ranked 19 places below his would number 10 opponent, did not have it all his own way after leading 6-3 from the first session.
Carter, runner-up in 2008 and 2012, made century breaks of 111 and 104 but he could not claw back the deficit as Dott dug in to progress with a gritty 10-7 success.
Dott said: "I certainly tried to attack the ball as best I could, when it was necessary.
"I think you've got to do that here, you're playing the best players in the world, you can't go into your shell and just try and tippy-tippy about, it doesn't work.
"I'm not the best at anything but I'm pretty good at everything and over the long games that's all you need to be."
Xiao, who had never previously progressed beyond the first round in Sheffield, defeated Day 10-4.
The world number 44 opened up a four-frame advantage on the Welshman and again pulled away to lead 6-3 after Day won three in succession.
Xiao then began the second session in fine form, making two half-centuries on his way to winning the first three frames.
A 98 from Day reduced the arrears slightly before Xiao set up a second-round meeting with world champion Mark Selby.
Day, a three-time quarter-finalist, said: "It was a bit of an embarrassing day at the office. My concentration was poor all day really.
"You want to play well on a big stage and today I didn't."
Elsewhere, 2010 champion Neil Robertson leads 8-1 over Thailand's Noppon Saengkham heading into Thursday's second session.