John Higgins draws level in the frame at 46-46 with three reds left on the table.

They're not in prime position, but he'll need all of them and probably up to the green to leave Neil Robertson leaving snookers.

Dennis Taylor
1985 world champion on BBC Two

What a chance for John Higgins now.

Neil Robertson's 77 break in the second frame is the highest of the match so far. It's not been a free-scoring classic yet, by any means.

He's up to 46 in his current visit, with five blacks and a blue following his six reds.

But now it's gone wrong. Robertson's only option to keep the break going is a tough plant to the middle, which hits the far jaw and stays up.

A slightly careless safety by John Higgins catches the brown and leaves Neil Robertson with a chance of a long red.

The 2010 world champion, who hasn't reached a semi-final at the Crucible for 12 years astonishingly, floats it in.

Will he find some fluency in this visit?

The first sessions of all four quarter-finals today have been close affairs.

Two players have 5-3 leads, another has ended 4-4 and neither John Higgins nor Neil Robertson will hold a decisive lead at the end of their opening session.

An indication in the stats as to why this match is locked level.

Namely, Wu Yize's 50% long pot success rate.

He goes for A LOT... when he gets them, he's in and when he doesn't, well his opponent is in.

Going to be fun to watch this one through to the end tomorrow.

These two are back on Wednesday at 14:30 BST for a marathon conclusion, playing back-to-back sessions in afternoon and evening.

John Higgins gets the points he needs to get over the line in frame six and we're all square with two frames of the session left to play.

Ken Doherty
1997 world champion on BBC iPlayer

Wu made some wrong choices for me there.

Hossein Vafaei finishes the stronger in the session when Wu Yize had been all over him, winning three frames in a row.

Vafaei will be feeling really good about himself.

Again, Wu Yize's risk-reward decision-making comes into question.

He plays some ultra-attacking shots to build a 20-30 point lead but goes for one tough ball too many on a long black with deep screw - having, strangely, shied away from trying to split two reds up from the blue a couple of shots earlier when it looked nailed-on.

The black careers off the jaws and leaves Hossein Vafaei a great chance to mop up the last two reds with colours - and he does exactly that.

A real rollercoaster session, that - Wu came from 2-1 down to lead 4-2 but Vafaei will be chuffed to come out level.

Sixth time lucky for Neil Robertson and a massive cheer goes around the Crucible.

But John Higgins has a pot to the middle or one to the green pocket if he wants to take it on.

He does and gets it, and lands on the yellow - advantage Higgins with a 38-point lead.

Neil Robertson is in a pickle here.

He's had three attempts to escape the snooker and three failures.

What the Australian doesn't want to do is hit the cue ball too hard and leave John Higgins in among the balls, so he's erring on the side of caution trying to hit a loose red just off the top cushion.

Make that four attempts now. The penalty points are racking up.

John Higgins ran out of position on 24 so another safety battle ensues.

Higgins knocks in a long red but doesn't drop nicely on a colour, so leaves Neil Robertson glued to the baulk cushion.

Robertson's attempted safety leaves a red right over the corner, but covered.

Higgins, 25-9 up in the frame, goes for the plant and - by hook or by crook - a red drops.

The Scot rolls up right behind the yellow and Robertson is bang in trouble now, with lots of reds in the open.

Again, has Wu Yize crossed the line between aggression and over-aggression?

Tough long red misses the mark and another chance gifted to Hossein Vafaei.

But oh dear, a terrible miss with the rest from the Iranian qualifier.

He can capitalise. A very steady 71 break - having lost three frames on the spin and not had a lot of table time amid that - gets Hossein Vafaei back within one.

A key final frame of the session to come - Wu Yize will be disappointed if he does not come away with an overnight lead. Vafaei will be delighted if he can head back to his hotel level.

Not the best of safety shots from John Higgins and Neil Robertson gets the first look in frame seven.

A missed black off the spot ends that break on nine.

A chance for an immediate reply for Higgins.

Image source, PA Media

Ken Doherty
1997 world champion on BBC iPlayer

I know Wu Yize is so confident but that might have been a time to batten down the hatches and play a good safety.

The reason I say that is because he had Hossein cold in his chair and he was getting on top of him - now he's thrown him a lifeline.

It's weighing up your options and the situation - it could be a little turning point in this first session if Hossein can capitalise.

The exuberance of youth, Ken Doherty called it in the previous frame.

But it can become overexuberance...

Wu Yize likes to roll the dice but well, no dice this time as he misses a long blue on a 29 break.

It hands Hossein Vafaei - mostly a spectator since the interval - a chance to get back into this.

Stephen Hendry
Seven-time world champion on BBC Two

You're waiting for someone to take this by the scruff of the neck and stamp their authority on it.

It's been a bit like snooker by numbers, if you like. Nobody's really taken charge of this quarter-final.

Meanwhile, the chair repair is complete and we're under way in frame six.

Steve Sutcliffe
BBC Sport at the Crucible Theatre

Perhaps it was a good job that Neil Robertson was not in his chair for much of that previous frame, given it appears to be broken.

Running repairs are currently under way, with someone attempting to fix whatever the problem is while both players shift out of the way.

Ken Doherty
1997 world champion on BBC iPlayer

He's got his potting boots on now.

His average shot time for that break was just 14 seconds which gives you an idea just how much he is growing in confidence.