What a shot that is from Mark Allen. A long plant onto the red looks to set him up on the black.. or does it?

There's just not enough room there to go for the shot and he plays for the safety shot instead.

He gets a second chance though as he gets back on the table and pots another long red and this time he is on a colour.

Can he clear up from here?

The players are back from their cup of tea, seeking to strike a first decisive blow after the interval.

"It's a very important mini session before their final session tonight, particularly for Mark Allen," says 1997 world champion Ken Doherty on BBC Two.

Wu and Allen are searching for a first World Championship title, and one of them will have a crack at the big one on Sunday and Monday.

In the other semi-final, John Higgins has his eyes on a fifth victory and is established as an all-time great already.

These are the big winners in snooker's modern era.

Image source, BBC Sport

Stephen Hendry
Seven-time world champion on BBC Two

We has stepped up this morning.

I thought he looked bang on it when he came into the arena. There were no smiles, it was just a cursory wave to the crowd.

It might be he's just not a morning person, but to me he looked on it.

I thought he had a different vibe about him and from the first frame his intent has been to just go out and pot all the balls. It's brilliant to watch.

Mark Allen, tapping his leg [in appreciation], I don't know about that because you're here to win the World Championship semi-final, not applaud your opponent, but it shows you how good he's playing that his opponent's appreciating it.

His strength is to attack and pot the balls, so that's how you play, you don't change your game just because you're playing someone like Mark Allen who's very good at the tactical side.

Image source, Getty Images

Mark Allen was born in 1986, four years after Alex Higgins won his second World Championship title and hugged toddler daughter Lauren as tightly as the trophy.

Allen was a boy of just eight when Higgins last featured at the Crucible in a World Championship.

So Allen's views about his fellow Northern Ireland cue star have mostly been shaped by watching video clips of the Hurricane, and from Allen's father's own memories.

Allen, who hails from Antrim, has spoken in the past about how Higgins had an influence on his career.

He said: "He was before my time, but it was probably watching Alex that got my dad interested, and that led to my dad taking me to the club, so there's the knock-on effect.

"I only see him on videos, but you hear all the stories from some of the players back home, from the amateur ranks, of how Alex was and it would have been great to have been around him then."

To follow in the footsteps of Higgins and Dennis Taylor by becoming a champion for Northern Ireland in Sheffield has always been Allen's aim.

"I got a small taste of that when I won the Masters," he said.

"The reception I got for that was beyond anything I'd had before and I imagine if I won the Worlds it would be on an entirely other level, so it's up to me to try and do it. We'd have open-top buses - I'd hire one myself."

Ken Doherty
1997 world champion on BBC Two

The way he's gone about himself this morning really is exceptional.

What a session of snooker we've been treated to this morning and hopefully there's be a lot more coming.

Brilliant break from Wu Yize. He's back on the horse. He fell off it yesterday but he's well and truly back on it now.

A 142, a 76 and now a 121 for Wu Yize who extends his lead to two frames over Mark Allen.

This is some real no-fear snooker from the 22-year-old who even received subtle applause from Allen in his seat when he knocked the brown in for his century.

A great mini session, from both players.

John Parrott
1991 world champion on BBC Two

He made a couple of breaks in the opening session of this match that were truly outstanding.

He had one break the other night with nine blues and two yellows. The cue ball was travelling around all over the place, but he was knocking everything in.

He's a bit of a fiendish potter as well as an accurate break-maker. It's a dangerous combination.

A lovely pot off the rest from Wu Yize to get a break going for himself. He follows that up with a couple of delightful positional shots on stray reds and he's back down near the pack again.

The 22-year-old leads 25-14 in the frame as he continues to build.

Mark Allen misses a long red to the bottom left and misses it by a distance.

Incredibly, in a rather open table of reds, the cue ball drops safely and leaves Wu Yize with nothing doing.

To the safety shots we go.

Stephen Hendry
Seven-time world champion on BBC Two

He's just all about getting in, winning the frames in one visit.

He's going to have to play the tactical game at some stage, but he's just so good to watch.

He's all-out positive the whole time, going into the pack early again, getting the balls open.

Wu Yize misses a red with the extension but on a break of 76, Mark Allen says that's enough and Wu retakes the lead.

Another very impressive visit from the young man.

This is some response from Wu Yize who is up beyond a half-century break in this frame.

The 22-year-old's current session pot success currently sits at 96% and he is right in the groove.

Steve Sutcliffe
BBC Sport at the Crucible Theatre

Mark Allen was clearly irked on Friday after the longest Crucible frame in history.

He was unhappy by the way the 14th frame was officiated and the perceived influence of Rob Spencer's chat with match referee Marcel Eckardt.

The Stockport official was dispatched from the tournament office, well into the deadlock, to warn there would be no time to restart the frame if a re-rack was called as the following match was soon due to start.

Although Northern Ireland's Allen did not see it that way and is sure to be fired up this morning.

Joe Perry
Former World Championship semi-finalist on BBC Two

Allen always seems to find a way back [from difficult situations]. He is more tactically adept than Wu.

You have to win some of the scrappy games and Mark Allen is going to win the vast majority of those.

We're back all square once again.

Off the back of that failed long red from Wu Yize, Mark Allen builds a break of 56 and Wu concedes the frame.

Back-and-forth we go.

A real good opportunity for Mark Allen to open up a commanding lead in this frame now.

He delivered a brilliant safety shot that forced Wu Yize into attempting a long red but the 22-year-old could only rattle the jaws of the pocket.

That has opened up the table now for the Northern Irishman to likely level this one back up, should all go to plan.