Shaun Murphy opens the seventh frame with a great long red.

A chance for a fourth successive frame to take the lead for the first time in this quarter-final?

John Parrott
1991 world champion on BBC Two

It was a fascinating frame.

From being 3-0 down in no time and having a couple of chances, 3-3 is looking great for Shaun.

Both players miss chances to pot the pink but it's Shaun Murphy who eventually takes a dramatic sixth frame that lasts about 42 minutes.

From 3-0 down, Murphy is back to 3-3.

Image source, PA Media

Oh my... DRAMA!

It was by no means a gimme, but Shaun Murphy misses a brown along the baulk cushion and lets Zhao Xintong back in.

The defending champion just needs the pink to win the frame - but misses!

Zhao leads by nine points.

What a fluke from Shaun Murphy!

On his fifth try, he changes his angle of approach to get out of the snooker and pots the last red!

And now the frame is at his mercy...

Shaun Murphy misses a long, straight red and, after a superb safety in reply from Zhao Xintong, Murphy finds himself bang in trouble tight behind the yellow.

Three misses and Zhao leads 57-53.

As Stephen Hendry said earlier (12:28 BST), this is turning into a key frame.

Zhao Xintong seizes the initiative with a tremendous long red and later leaves Shaun Murphy snookered on the final red. Murphy hits it, but knocks the black in at the same time.

The Chinese player trails by eight points with that solitary red left.

Mark Allen got in first with 25 but Barry Hawkins knocks in a 75 break in reply to move back in front and ensure he'll be at least level at the end of the first session.

Hawkins has now made four half-centuries to go along with his contribution of 114 in the second frame.

Stephen Hendry
Seven-time world champion on BBC Two

This could be the most important frame of the session so far.

The fact that Zhao has gone off the boil a little bit, Shaun has got to take advantage.

Image source, PA Media

Zhao Xintong misses a cut-back red to the corner, allowing Shaun Murphy back to the table.

Murphy then pots an excellent red with the rest and starts another break.

With four reds left - all in relatively safe positions - Murphy is seven points ahead.

Shaun Murphy gets the next chance but can only add 15 points to his score.

A straightforward pink off the spot is missed - how costly will that proved to be?

There are still plenty of safe reds so Zhao Xintong has work to do to build a healthy lead.

It's been a bit of a stodgy start to the sixth frame, with neither player able to gain any sort of momentum.

The table is pretty awkward, with seven of the 12 remaining reds on or near cushions.

Zhao Xintong has a 17-point lead.

No comeback for Barry Hawkins in frame six and Mark Allen levels things up at 3-3, his earlier break of 64 doing the damage.

There hasn't been more than one frame between these two experienced players in the opening stages of their quarter-final.

Two more frames to play in this session.

Stephen Hendry
Seven-time world champion on BBC Two

There are just signs that, after a blistering start to this match, Zhao Xintong has gone slightly off the boil.

In this frame, there have been a couple of careless shots.

For me, he's just lost a little bit of focus since the interval.

Mark Allen gets into a strong position in frame six but misses frame ball - a straight red along the top cushion.

43 points remaining and Barry Hawkins is 37 behind.

Zhao Xintong has Shaun Murphy snookered on all reds behind the yellow early in the sixth frame.

Murphy tries to glance off the side of the pack off two cushions but needs five attempts in all before finally managing it, giving away 16 penalty points in the process.

Image source, PA Media

John Parrott
1991 world champion on BBC Two

On Shaun Murphy's excellent pot on the black to the left middle:

That was a very good end to the frame. Next time you go to the table, have a look from the black spot to the middle and see how much pocket you've got to look at.

Shaun Murphy was excellent in the closing stages of the fifth frame, dominating the safety exchange and earning an opportunity to clear the final five colours - which he does to reduce his deficit to a single frame.

Stephen Hendry
Seven-time world champion on BBC Two

Two or three shots in that visit were world class from Shaun Murphy.

The black to the left middle was the pot of the session.

An interesting decision from Shaun Murphy, who attempts to free the safe green when potting the last red and getting down for the black.

He's left with a black off the spot into the left middle, which he needs to pot or he'll need a snooker - and he gets it! Incredible shot!

He has to play a safety off the green, he plays it well, and he's right back in the frame.