Final (best of 35 frames)
O'Sullivan takes a 10-7 lead over Selby into Monday's session
O'Sullivan hits a break of 131 in the 14th frame
Selby wins final two frames to reduce deficit
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Look back at the tournament's ups and downs in Highlights
Selby moves to within one frame by taking the seventh of the day. He has not made a break of higher than 37 yet, but has still fought back from 3-0 down and now trails by only 4-3.
Ronnie O'Sullivan 4-3 Mark Selby (36-72)
From the Steel City of Sheffield to the sunny side of the Costa Del Sol, quarter-final loser Judd Trump is taking it easy by the pool.
Image source, @judd147tHe tweets a picture of himself, external on his holidays by the pool. It looks a bit warmer where he is than at the Crucible.
O'Sullivan gives away 12 points in fouls as he can't hit a red with a two-cushion escape. Selby is now ahead 70-9, with four reds left on the table.
Selby now leads by 58-9, but there is still some mileage left in this frame. O'Sullivan comes to the table with the cueball snuck tightly behind the green.
Mark Selby is 42-8 ahead in the seventh frame but ends up tight on the cushion after overdoing a pot on the blue.
However, O'Sullivan can't take advantage when he misses a pink ball, off the brown spot, to bring Selby back to the the table.
The Rocket v The Torturer. Ronnie O'Sullivan admits that Mark Selby has the potential to get under his skin and the pair are 3-3 in tournament finals.
It is a classic sporting clash of personalities. The flair of O'Sullivan fought by a tenacious Selby.
Image source, Getty ImagesThe duel is somewhat reminiscent of tennis rivals John McEnroe v Jimmy Connors in the 1980s. The enigmatic McEnroe versus street fighter Connors, who loved to interject with the crowd.
Which characters from other sports do O'Sullivan and Selby share similar traits with? Let us know on Twitter, using the hashtag #bbcsnooker
Sean Robinson:, external If Ronnie O'Sullivan wins this tomorrow he should get BBC Sports Personality Of The Year.
Robert Dawson:, external Sometimes it's laughable how good (King) Ronnie O'Sullivan is.
Lilalovesf1:, external Obviously I want Ronnie to win, but Mark is such a nice bloke and a great snooker player that I can't help but like him.
John Parrott
Former world champion on BBC TV
"O'Sullivan should have been 4-0 ahead at the interval and, after being pegged back to 3-2, it was important for Ronnie to win that frame."
What is it like to be on the receiving end against Ronnie O'Sullivan?
Image source, Getty ImagesBarry Hawkins, after losing his semi-final 17-7 to O'Sullivan, said: "Any little mistake against Ronnie is magnified. I felt like I was in a boxing ring and have had 12 rounds with [Mike] Tyson (pictured). I just feel mentally bashed to be honest. I am glad it is all over."
Ken Doherty
Former world champion on BBC TV
"He was buzzing around the table. It was an important frame for Ronnie and that opening pot was fantastic. He needs to keep Mark Selby under pressure as Mark is one of the top match players."
O'Sullivan moves 4-2 in front as a break of 63 sees him take his first frame in three.
The sixth frame was the second fastest of the game so far lasting 11 minutes and six seconds. O'Sullivan, after the first six frames, has 398 points and Selby has 171. Selby's highest break in this session is only 37.
Ronnie O'Sullivan 4-2 Mark Selby (80-8, O'Sullivan 63 break)
O'Sullivan may have lost the last two frames, but he looks back to his best in the sixth. He may soon be reclaiming his two-frame advantage.
We asked for your questions on Twitter, to be answered by six-time world champion Steve Davis.
Throughout today we will be publishing some of his answers.
Harry asks: "I'm a junior snooker player and I was wondering if you have any tips on how to improve long potting?"
Steve Davis: "Don't underestimate the practice technique of hitting the ball up and down the spots to improve your centre ball striking, along with plenty of long, straight diagonal blues. Practice as often as you can potting long balls."
Image source, Getty ImagesIn case you were wondering, the fifth frame was the longest of the match so far taking 32 minutes and 13 seconds - almost four times as long as the third frame which took just eight minutes and 57 seconds.
O'Sullivan's safety success after five frames stands at just 70% in comparison to Selby's 76%, although his pot success rate of 94% is far superior to Selby's 83% ratio.
Tom Swain:, external I dislike maverick clappers at The Crucible. "Oh look, he's hit a ball. I will clap that." Let's save clapping for good play.
Gracie Girl:, external Ronnie is lethal when he gets on that table. I still want Selby to win though.
FM Hints:, external This isn't even a snooker match. It's simply Ronnie allowing someone else a chance to share his table.
Selby lost the first three frames and looked set to be steamrollered in the final. But he has fought back and battled to win two frames in a row now.
The critical moment came when O'Sullivan went in-off as the cueball disappeared into the pocket and Selby, who had earlier missed two shots earlier in the frame, remains composed to pull the score back to 3-2.
Ronnie O'Sullivan 3-2 Mark Selby (47-68)
Mark Selby misses two attempts at reds when he looks in a strong position to take the fifth frame. The first miss came when he held a 44-15 lead.
He comes back to the table snookered behind the pink and three points behind with the colours remaining.
Image source, Ken DohertyThe 1997 champion Ken Doherty posts a picture on Twitter of the view from the BBC booth,, external sitting along with presenter Hazel Irvine and 1991 champion John Parrott.
It is the longest frame of the final so far with both players battling to gain control of a safety battle. But there is a small chance for Selby when O'Sullivan leaves on a long red, which the man from Leicester sinks.
The World Snooker Championship is played over 17 days at the Crucible, with the final taking over the last two days.
So how do players cope with the gruelling nature of the tournament, on and off the table, in order to be crowned champion on the first Bank Holiday Monday in May?
Image source, Getty ImagesBBC Sport's Shamoon Hafez spoke to three former champions - 1991 winner John Parrott, seven-time champion Stephen Hendry and 1997 victor Ken Doherty - to find out how difficult it is to stay focused and manage your energy.