|Venue: Crucible Theatre, Sheffield Dates: 18 April-4 May|
|Coverage: Watch live on BBC TV, HD, Red Button, Connected TV, online, tablets, mobiles and BBC Sport app. Full details here.|
Barry Hawkins produced a brilliant fightback to snatch a 13-11 win over Mark Allen and book his place in the World Snooker Championship last eight.
The 2013 finalist was made to scrap from 11-8 down in the final session.
Four-time champion John Higgins was knocked out after losing 13-9 to China's Ding Junhui while Graeme Dott lost 13-5 to Essex's Stuart Bingham.
And favourite Ronnie O'Sullivan came back from 2-0 down to take the first session 5-3 against Matthew Stevens.
O'Sullivan, looking for his sixth Crucible title, showed his frustration by banging his cue on the table after missing an easy red in the third frame.
But he soon found his form. Breaks of 100, 63 and 61 gave him the advantage, before he pinched the seventh frame after Stevens had made 55.
The Welshman avoided losing six on the bounce by taking the final frame of the session with a 71.
Meanwhile, 2010 champion Neil Robertson produced some exceptional snooker to take a 6-2 lead over two-time runner-up Ali Carter.
The Australian knocked in three breaks over 50, two tons and potted a superb red from the top cushion in the final frame of the session to take a commanding lead.
Barry Hawkins 13-11 Mark Allen
Englishman Hawkins, a semi-finalist last year, was thrilled with his comeback win.
"I have done it again and I don't know where it came from. I seem to do that quite a lot," he said.
"I am delighted to still be in the tournament and beat somebody of Mark's calibre. That gives me great confidence for the next round.
"He's a gentleman. It was played in good spirit. I dug in and felt I was getting stronger towards the end."
Northern Irishman Allen, who reached the last four in 2009, added: "The last session was frustrating. Barry did a good job and froze me out.
"Any chances I had were half-chances and the balls were awkward."
Ding Junhui 13-9 John Higgins
Ding, the world number three, started the day 9-7 up on the Scot before taking three of the first four frames. Higgins tried to come back into it, but the Chinese player held his nerve to advance.
The 28-year-old believes he is playing a level of snooker that could help him win his first world title.
"I hope I'm going to win the tournament. I believe I can - I have the form to win any tournament," said the former Masters and UK champion, who reached the semi-finals in Sheffield in 2011.
"I think I can play better."
Higgins, who had led early in the match, said that Ding is a real challenger.
"Ding's cue ball control reminds you of Steve Davis in his prime - he makes everything look ridiculously easy. He made a couple of pressure clearances which mean he is probably ready to win the world title," the 39-year-old told BBC Sport.
"He has grown up and is more at ease within himself and seems ready to tough it out."
Stuart Bingham 13-5 Graeme Dott
Bingham, who reached the last eight in 2013, needed only two frames to seal victory, finishing with a break of 104.
"It is a fantastic feeling to beat someone of Graeme's level 13-5," said the 38-year-old.
"I made a 64 in the first frame and that settled me down. (That) calmness stayed me with throughout the match."
Dott, who won the title in 2006, said: "I never really felt it was a 13-5 game. Last night, I could have won the last two frames, but losing the second-to-last frame killed me.
"It's not nice to lose like that."