|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.|
Five-time winner Ronnie O'Sullivan was surprisingly beaten in the second round of the World Championship, losing 13-9 to Ali Carter in an ill-tempered match.
O'Sullivan, who had lost to Carter just once in 17 previous meetings, appeared to barge into his fellow Englishman's shoulder during the 19th frame.
O'Sullivan trailed Carter 5-3, which was extended to 8-3, before he hit back for a 9-7 overnight deficit.
But he could not get ahead as Carter kept his composure for a famous win.
After the two players shook hands at the end, two-time finalist Carter - beaten in both the 2008 and 2012 finals by O'Sullivan - celebrated wildly in front of the Crucible crowd.
Carter played down the clash with O'Sullivan, saying: "It was nothing. He is walking to his chair, I'm walking to the table, we brushed shoulders, it's no big deal.
"Ronnie is a master in all areas, a master of one-upmanship, but I was going to do whatever it took to win."
O'Sullivan added: "I've known Ali since he was 10 years of age. Sometimes it gets a bit tense out there but it's all behind us."
Carter ends 'Ronnie' show
Carter, who has had lung and testicular cancer, as well as Crohn's disease, recorded his first win over his fellow Essex player in a ranking event.
He had said after his first-round win over Graeme Dott that "it was the Ronnie O'Sullivan show all the time" but there are other players competing in the event too.
And putting O'Sullivan under pressure from the first session paid dividends.
"In the past I've been guilty of Ronnie intimidating me like he probably has with other players," said Carter. "It's nice to finally get one up but I feel like a different person since I last played him in 2012. I've been through so much in my life.
"He's got such a presence and he's such an amazing snooker player but he wasn't having it all his own way."
With defending champion Mark Selby suffering a shock first-round exit, the event has now been thrown wide open.
Having won a record-equalling five ranking titles this season, O'Sullivan has been the tour's form player - but he failed to showcase his brilliance in Sheffield.
He was not at his best against Stephen Maguire in the first round and was outplayed by Carter on this occasion. It was a throwback to previous years when O'Sullivan has crumbled at snooker's biggest tournament.
And the temperature rose when he shoved Carter while going back to his seat in the 19th frame.
O'Sullivan had put Carter in a snooker on the green ball and while walking back to his seat, stuck an elbow into the arm of Carter, who seemed to laugh it off, before a tetchy exchange took place.
Carter kept his cool and took the frame for an 11-8 lead. O'Sullivan claimed the next but missed a simple blue on a break of 54 and Carter cleared up, with a further 51 sufficient for victory.
"He was the better player throughout the whole match," O'Sullivan said. "I battled back last night but I was second to the punch every time.
"You can't win World Championships when you're having bad spells like that. Ali is a tough competitor, he's always had that feisty character. He was strong out there and deserved his victory."
Hawkins into quarters
Meanwhile, former runner-up Barry Hawkins survived a scare to beat debutant Lyu Haotian 13-10 and reach the quarter-finals.
China's Lyu recovered from 4-0 and 8-3 down to level the contest at 10-10, but missed chances allowed Englishman Hawkins to win three frames in a row.
"He just kept potting balls and did not look flustered. I could not shake him off," said Hawkins.
He will face China's Ding Junhui or Scot Anthony McGill in the last eight.
Englishman Kyren Wilson completed a comfortable 13-5 victory over Welshman Jamie Jones and sets up a repeat of this year's Masters final against Mark Allen in the next round.
Two-time champion Mark Williams opened up a slender 5-3 lead over Robert Milkins. They resume on Sunday at 14:30 BST.
Four-time champion John Higgins, runner-up to Selby last year, whitewashed Jack Lisowski 8-0 in the first session of their second-round tie. They continue on Sunday at 14:30 BST.