|Betway UK Championship|
|the place of event: York Barbican dates: November 27 – December 9th|
|coverage: Watch live via BBC Two, the BBC's iPlayer, the BBC Red Button, the Connected TV, the BBC Sport web site and the mobile application from December 1st.|
World number one Mark Selby has suffered 6-3 first round loss to amateur James Cahill in one of the biggest shocks in the recent history of the UK.
The double former champion fought against 22-year-old 126th seed, who dropped the main tour at the end of the 2016-17 season.
Cahill led 4-0 and 5-1 and won a top-long pink victory in nine.
"It's a big win. I hope they can take on the confidence," he said.
"The standard was not incredible, but winning the world number one, such a great player, is great.
"I am good enough to compete with the best, but I have to be more consistent."
Cahill did not pass the first round of events this season but found his form at York Barbican.
Selby, who lost last season to Scott Donaldson in the second round, managed to score only 79 points in the first four bets before reaching the board to renew his hope of returning the trademark.
Cahill got his opponent in trouble on the colors and took the next box by placing pink and black.
In Leicester's men he suddenly found his shape, taking the next two frames and hitting 103 in the way to reduce Cahill's 5-3.
But Cahill played the ninth box without nervousness to win on the other, where he faced Sunny Akian.
"I was all garbage," Selby said. "I'm excited because it's a great tournament. I felt flat, which is weird.
"I've played well lately to do this, it's weird. There are not many positive items."
While Selby fought, another two-winger in the UK and world champion Mark Williams had little trouble watching their amateur opponent Adam Duffy.
The 43-year-old Welshman, the winner of 22 titles, has won four-half a century in a convincing 6-2 win.
Williams, who admitted neglecting his practice since winning the world title in May, showed several signs of rust.
"My performance was fine, but it was pretty dirty," he said.
"If I could win this tournament three times, that would be fantastic. This will probably be my last tournament before Christmas, so I want to try and go through and see what's going to happen."
The second round of this year's tournament starts on Saturday, December 1st, when it's live on BBC BBC, BBC iPlayer, Red Button, Connected TVs and BBC Sport website and app.
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