Match Notes:

 Selby holds his nerves together to book his second semi final appearance.

Mark Selby looks strong, Ronnie looks rocky and Selby needs one more to book his semi final place.

Selby gets his act together to level the match again. Both players have gone out to compose themselves.

Well we've hit the 'miss' stage of the match. In successive shots Ronnie has missed an easy red and an easy green and Selby has missed two dolly reds. The nerves are showing now.

A brilliant century by Selby closes the gap to one frame again. This is another Crucible classic.

Selby will be kicking himself during the interval. He missed the black when leading by 36 and O'Sullivan stepped in with 75.

Selby closes again, getting a second chance after missing a very easy red to centre on 49.

45 is enough for Ronnie to regain his two frame lead.

O'Sullivan left a red in the jaws and Selby made 40 to take the first frame of the night and close to within a frame. I think we're in for a very exciting evening on both tables.

Selby rattles in 62 in the last frame of the afternoon but is still giving Ronnie two frames start tonight.

Ronnie was eying up a maximum early in frame 16 but went in off trying to stay on the black and Selby has whistled through the frame with a ton to pull one back.

O'Sullivan will hold the lead ahead of tonight's final session. He's forged ahead into a 9-5 lead now.

This is a fabulous session, O'Sullivan rattles in a brilliant century to go 8-5 ahead.

Now Selby runs in a frame winning break and it looks like both players are hitting form this afternoon.

Selby misses a blue to the yellow pocket and Ronnie rifles in 89 to go two frames ahead. This is a totally different O'Sullivan from yesterday.

It's a blistering start by Ronnie today and a shattering start by Selby and a foot in the mouth afternoon by Rob Walker. Ronnie smashes in 92, Selby smashed his glass and Rob Walker introduced Steve Davis as Dennis Taylor - it's all going well!

A thoroughly scrappy session ends 4-4. Both players will be looking to play better tomorrow.

O'Sullivan missed a skinny green down the rail and Selby cleared up to nick the lead on the black.

Ronnie levels with a run of 67, Selby conceded 66 behind with 67 still on.

O'Sullivan missed the blue early in the frame and Selby has capitalised to regain the lead. Ronnie doesn't look fully focussed on this match yet.

Somehow Ronnie has levelled at the interval but it's a poor performance so far and at times he's looked obviously bored, to the point of standing watching the match on the other table.

Selby pumps in 84 to level.

The points are piling up for Ronnie as he had Selby snookered and after 42 minutes Ronnie takes the opener.

The first frame has now been in play 31 minutes and we're no nearer resolving it.

There are 6 reds, all in a clump on the top cushion, with the black on guard duty amongst them. This could take a while to sort out.

Ronnie's had the first chance but lost position on 35 and there's now a long safety battle in progress.