This is the penultimate frame of the first session.

John Parrott
1991 world champion on BBC Two

Do you know the best thing for this match? A good night's sleep.

They'll come back tomorrow far better - they're both having hangovers from their last matches.

When you're a little bit tired, you have concentration in fits and starts, and that's what's happening.

Some of the balls they're missing are inexplicable.

Stephen Hendry
Seven-time world champion on BBC Two

The red and the green were beautifully struck shots by John Higgins. He's played himself into this.

Shaun trudged out [at the end of the frame] with his hands in his pockets and it was a slow walk. When he's flying, he's bounding around.

He's missed a bit of a trick here.

Another great pot on the black from John Higgins and he's on the yellow, but with not the best angle to get nicely on the green.

He pots it from mid-distance and clears up to the pink to level the match.

A superb break, a confidence-booster for Higgins.

John Higgins is 17 points behind when he floats in a long red, knowing he would only leave the ball he was playing.

After another couple of pots, he screws back the full length of the table off the green to get on the last red, and drills it along the top cushion into the corner pocket.

Great pot - but he's not ideal on the black...

Misses from both players continue to be the theme of the afternoon.

Shaun Murphy is next in and moves into the lead with four reds left on the table.

Snooker has been around for more than 150 years so it's not often we see something different, but Shaun Murphy's break-off has been a talking point during this year's World Championship.

The 2005 world champion is purposely opening the reds when he has the first shot in a frame - an aggressive play which either forces his opponent to take on a long red or leaves them needing to play a safety that covers everything.

It seems to have been effective so far.

Speaking of breaks, there have been four of 140 at the Crucible Theatre and that is the highest of this year's World Championship so far.

Mark Allen has done it twice, while Barry Hawkins and Shaun Murphy have done it once.

John Higgins' highest break of the match so far is 36.

His latest effort ends on 18 when a cannon from the blue into the reds go awry.

Once more, John Higgins is searching under the table for extra equipment to play a difficult shot.

He has to bridge over the pack of reds to play a pot on the black, so he has to put the rest on top of the spider to get enough height.

The black wobbles a little bit in the jaws before dropping in the pocket.

A decent chance from here, although the black is only available in the left corner at the moment.

The semi-finalists have guaranteed themselves at least £100,000 in prize money. Reach the final and the numbers go up drastically.

• Winner: £500,000
• Runner-up: £200,000
• Semi-finalists: £100,000
• Quarter-finalists: £50,000
• Last 16: £30,000
• Last 32: £20,000
• Highest break (qualifying stage included): £15,000

John Parrott
1991 world champion on BBC Two

John Higgins is hanging on in there - if you were in Shaun Murphy's camp you'd be kicking yourself.

John's under the weather, Shaun's not been brilliant but that miss on the blue is up there with the worst shot of the championship he's played.

He's in a session where he could be kicking on and getting a bit of distance, but he's not doing it.

Stephen Hendry
Seven-time world champion on BBC Two

You've got to try to win frames against the likes of John Higgins when you're not at your best and he [Shaun Murphy] has not been able to impose himself on this semi-final.

In the first frame, you thought: "Here we go, Shaun's continuing the way he's playing and he's going to have a big win in this session."

But he's not kicked on from that and that'll be concerning.

There's obviously a long way to go but, the way John's played, Shaun should arguably be well in front.

Dennis Taylor
1985 world champion on BBC Two

It's been a frame not far off 39 minutes, a tactical frame, but it was the Wizard who got one over the Magician.

A few more pots and Higgins wins the frame. He's back within one.

John Higgins is in prime position to win the frame now - he's 29 ahead with 35 left and has Shaun Murphy in a snooker.

The escape doesn't go to plan, with four points given away, and it'll take some time to get the balls to get back in place because a few were disturbed!

Higgins potted a tremendous red into the middle before laying the snooker - there didn't appear to be room but it squeezed past the pink on its way through. Like me trying to get out of a multi-storey car park.

Murphy hits the red at the second time of asking but leaves it over the corner from long range for Higgins...

John Higgins is able to play a thin clip off a red to get back to baulk and end that stalemate - albeit by using seemingly every bit of equipment from under the table to reach the cue ball.

It's a great safety but Shaun Murphy replies in kind, leaving Higgins in the jaws of the yellow pocket and in trouble.

The Scot plays it well but leaves Murphy a tempter - which he is unable to pot. Another chance for Higgins, but not an easy one.

This is one of those frames in which the balls have gone into really awkward positions and dictated the type of frame it will be.

Three reds left on the table and the highest break in this frame has been 12.

Higgins is 32-18 up with 51 points available.

There's going to be a little bit of a stalemate here as the three reds are in a small cluster and it's a bit tippy-tappy. We're desperate for a touching ball to occur, otherwise this might go on for a while.

Joe Perry
Former World Championship semi-finalist on BBC Two

Shaun has got John where he wants him but he can't keep giving John these chances because John won't continue to play badly and miss balls. At some point, he'll get going.

Dennis Taylor
1985 world champion on BBC Two

Shaun walks away and he can't believe he's missed the easiest of pots - that has to be a little lapse in concentration.

Wow - how has Shaun Murphy missed that? A blue to the corner that he'd expect to pot 999 times out of 1,000.