World Snooker Championship 2018: Robert Milkins beats 2010 champion Neil Robertson
|2018 World Championship|
|Venue: Crucible Theatre, Sheffield Dates: 21 April - 7 May|
|Coverage: Watch live across BBC One, BBC Two, BBC Red Button, Connected TV, the BBC Sport website and mobile app.|
Former champion Neil Robertson was beaten 10-5 by qualifier Robert Milkins to become the sixth seed to go out in the World Championship first round.
World number 10 Robertson was erratic with his potting and seemed out of sorts in a largely scrappy match.
The Australian, 36, took the first two frames to reduce the 6-3 overnight deficit to 6-5 at the Crucible.
But Gloucester potter Milkins won four in a row to set up a last-16 match with another former champion, Mark Williams.
Robertson joins top-16 players Shaun Murphy, Luca Brecel, Stuart Bingham, Marco Fu and defending champion Mark Selby in exiting in this year's first round.
Milkins, who also beat Robertson at the first-round stage in 2013, looked nervy in an error-strewn start to the second session.
But he regained his composure as Robertson's struggles became increasingly obvious, not helped by having to replace his cue tip before the resumption.
Milkins, 42, made the most of an unlucky Robertson kick to win frame 12 and Robertson's potting betrayed him in the next frame, which the world number 37 took to move 8-5 up.
From then on there was no way back for the 2010 champion as the match finished without either player scoring a century break, although Milkins made seven breaks of 50 or more.
"I played well in the first session and put a lot of pressure on him to start with and that probably carried me on through the rest of the match," Milkins said.
"It got a bit dodgy when he got back to 6-5. I was getting a bit slow, taking too much time but all of a sudden I got fluent again and saw it out quite well.
"He missed a few more balls than I thought he would but I put that down to me putting pressure on him."
On the other table, world number four Judd Trump took a lead into Thursday's concluding evening session after going 6-3 up on debutant Chris Wakelin.
Wakelin made the tournament's highest break so far with a 141 in frame five, but that was surpassed later on Wednesday by world number 17 Ryan Day, who hit a 145 as he built a 6-3 lead over number 14 seed Anthony McGill.
In-form Williams closes out victory
In the morning session Williams, the 2000 and 2003 winner, had little trouble in overcoming Milkins' fellow English qualifier Jimmy Robertson.
The 43-year-old was in total control at 7-2 up after Tuesday's first session and eased through despite losing the first two frames.
He responded by scoring back-to-back centuries for a 9-4 lead, and although Robertson took the next frame, Williams closed out victory.
Williams has returned to the world's top 10 this season with the help of ranking event wins in Northern Ireland and Germany that have taken his career tally to 20.
He scored three centuries and four breaks of more than 50 in beating Sussex qualifier Robertson.
"I am coming into the Crucible playing the best stuff I have played for many years. Who knows if I can win it, but I have as good a chance as anyone," Williams said.
Higgins and Un-Nooh miss maximum chances
Four-time champion and last year's runner-up John Higgins saw off Thailand's Thepchaiya Un-Nooh 10-7 in a gripping, attacking match where both players came close to getting maximum breaks.
Higgins, a 30-time ranking event winner, had a 147-chance in frame eight after potting 13 reds and 13 blacks. But he missed a difficult 14th red after leaving himself hampered by the blue.
Crucible debutant Un-Nooh went even closer in frame 12, but rattled the jaws with the 15th red after he appeared to have done the hard work.
Higgins led 6-3 after the morning session, but Un-Nooh remained impressively calm under pressure and won three of the next four frames to trail by one at 7-6.
Un-Nooh continued to go for his shots - an approach which eventually proved his downfall against the wily 42-year-old Scot, who won the next two for a 9-6 lead before getting over the line.