Zhou's break comes to a halt at the yellow, but O'Sullivan then leaves the same ball hanging over the top right pocket.

Zhou, who had been 64-0 behind then snatches the frame 65-64, the third time today he has won a frame on the black.

O'Sullivan, despite some superb, beautiful breaks, remains yet to be ahead in this match. He needs to win three of the next four frames or he is out at the first hurdle.

It is a really good match on table one and Ronnie O'Sullivan, who trailed 2-0 earlier on, was on course to move ahead for the first time

He missed a red at 28-0, but it was not punished and then raced to 64-0.

Zhou came to the table with 66 points still possible. and he's still going, now on the colours, looking for what could be a vital steal.

Ronnie O'Sullivan misses a red to the left corner but Zhou Yuelong fluffs his chance to get some points on the board with a wayward attempt to the left middle.

And he's left 'The Rocket' in.

Lei Peifan has largely been frozen out on table two with Mark Selby in superb form, but now the 22-year-old world number 31 has a frame to his name thanks to an excellent break of 78.

From a little earlier. Ronnie O'Sullivan at his best.

Back on terms. Will this go to a decider? Ronnie O'Sullivan wins another frame in next to no time at all with a run of 94.

Majestic. Mark Selby recently won the Champion of Champions and knocks in a century break as he heads into a 5-0 lead in this best-of-11 encounter.

The Englishman must fancy an early dart. He has been far too good for Lei Peifan so far this afternoon.

Zhou Yuelong has one tricky ball here, the brown.

But he dispatches that into the top left corner and gets on the blue. In goes the pink and now the black.

What a result for him to take that frame.

Oh my. A mistake from Ronnie O'Sullivan as the white rolls into the corner pocket. An easy starter for his opponent.

Can Zhou steal the frame and regain some momentum?

Back to the action and Zhou Yuelong makes a right mess of safety shot up in the baulk area. It gives Ronnie O'Sullivan a look at a long red to the bottom left corner and in it drops.

He is off and running again and zips into a 62-15 lead in the frame before he breaks down.

Michael Emons
BBC Sport at York Barbican

Image source, Michael Emons

The mid-session interval is a time for the spectators to get out of their seats and have a look around the venue.

There are plenty of things to keep you entertained if you don't fancy just going to the bar. You can have a look at some of the best trophies from the sport - the World Championship trophy (above left) and Masters trophy are both on display.

Alternatively, you could feel inspired and head to the fanzone, where you can try your hand at the mini table or the main challenge on the full size version.

Today's challenge was a throwback to the old classic Big Break era - pot as many balls as you can. Ten reds are set up and you have 60 seconds to clear as many as possible. A lot of running around the table from those frantic to out-do their mates.

Alternatively, you can watch the professionals on the practice tables in the next room. Barry Hawkins, who plays David Lilley later on today, has just been going through some practice drills.

Image source, Michael Emons

Image source, Michael Emons

Image source, BBC Sport

Now then, we've already seen a record 16 147s this season but will we get any more during the televised stages of the UK Championship?

And what's behind snooker's 147 boom?

Have a read of this piece from BBC Sport's John Skilbeck, who has watched more than a fair few during his time covering snooker.

One foot in the last 16 for Mark Selby? He reels off his fourth consecutive frame and is two frames away from a whitewash and match against Ronnie O'Sullivan or Zhou Yuelong.

Stephen Hendry
Seven-time world champion on BBC Two

The dangerous thing when you are playing Ronnie is that you can become a bit hypnotized by it because it is so good to watch.

You find yourself admiring it. There is nobody who can make breaks like he can. To control the cue ball at that speed is genius.

Mark Williams
Three-time world champion on BBC Two

Unbelievable. You are sat in your chair two nil up and you are 2-2 in 10 minutes.

He's had a 70 and a hundred. It's frightening how quickly he can make them. When you are sat there watching you can't believe he can do it so fast and make it look so easy.

Ronnie O'Sullivan compiles 123 and gets back to all square as the players head for a little break.

Dennis Taylor
1985 world champion on BBC Two

Zhou Yuelong will be pleased the interval is coming along now.

This is vintage stuff from Ronnie O'Sullivan. He is up to 80 in no time at all and is still at the table.

Zhou Yuelong leaves Ronnie O'Sullivan a long red to the bottom right corner. How many can the Englishman make from here?