Luke Littler misses double 15 three times but it doesn't matter as Luke Humphries is too far back - and the 16-year-old lands double four to get the final back on level .

Image source, PA Media

Humphries emerges from that sticky spell by breaking Littler's throw with a double 20 finish.

But the teenager starts the next leg with a 180 and still has two chances to win this set.

Wayne Mardle
Five-time world championship semi-finalist on Sky Sports

Luke Littler is on the ascendancy right now even though he's behind in the match. Luke Humphries is going through a sticky spell.

Yes, he can, helped by Luke Humphries making a bit of a mess of a 71 finish.

Cool Hand didn't even get a shot at an outer double, having to go for the bullseye instead. He misses and Luke Littler tidies up double 20.

What do you do when you lose a set?

Brush it off and break the world number one's throw at the start of the next set.

Can he maintain the advantage though?

Ali: Come on Humphries! Littler Luke is great but Humphries has worked so hard for this. Go grab it.

Paul: Getting seriously annoyed that no credit is being given to Humphries here.

Gill: I'm hoping that Luke Humphries wins. Really impressed with how Littler plays and his composure, but he's going to be around for a long time and his time will come again.

Wow. Brilliant from Luke Humphries.

A big 180 in the middle of that fifth and decisive leg gave him the advantage and he capitalises to move back ahead.

Luke Littler pinched the previous set from two legs down - and Humphries has done it right back to him.

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Dominant hold of throw from the world number one.

So Luke Littler must hold his own throw to take the set.... big leg coming up.

Luke 'The Nuke' Littler misses two darts at a double for the set - and Humphries punishes him with double eight to break straight back.

Anna: Darts on in my office in America. Colleagues crowding in to watch with basically no idea on what's going on. But loving it.

Jay: I'm not sure if Littler understands the impact he has made, the whole country has stopped to watch... the darts. This isn't football or Ashes cricket, it's the darts. Fair play to him, hope he has great around him and the media give him some privacy.

And now Littler has a chance to break throw as he hits 177 to leave double 20...

And he hits it first dart! What a turnaround - he lost five straight legs and has won the next five.

Luke Littler is under pressure on throw in the opening leg of set three.

Luke Humphries is sat on 60, waiting his chance, with Littler on 80.

That chance never comes as the 16-year-old takes out double top.

They're going to need to change this dartboard mid-match the way it's going. Treble 20 bed is taking an absolute mullering.

No surprise - these pair have the most 180s in the tournament.

Martin: It's taken Littler a while to warm up, but he's there now. This should be back and forth.

Andrew: All my seven-year-old son has wanted to do over the last week or so is either watch the darts or play darts. Luke Littler is truly inspiring young people. And 142 and Shanghai to level the match? Wow!

Joss: Am I the only one who wants Luke Humphries [to win]? Yes Luke Littler is 16 but he has so much time whereas Humphries, no. Also I feel bad for Humphries because everyone is against him.

BBC Sounds

The latest pop-up episode of The Sports Desk podcast on BBC Sounds is dedicated to Luke Littler's amazing emergence over the past three weeks.

Jane Dougall is ed by semi-professional darts player Deta Hedman, who has known Luke since he was just ten years old, and darts journalist Chris Hammer from Sporting Life, who believes the teenager’s achievements aren’t a flash in the pan and that he will go on to emulate the success of other sportspeople like snooker's Ronnie O’Sullivan.

We also hear from PDC chief executive Matt Porter who talks about the challenges of the World Championship for someone as young as Luke and how he’s been coping with the pressure of playing in front of the Alexandra Palace crowd.

Check it out here.

Still hugely early doors, of course - the final is first-to-7 sets.

Although the speed these two are throwing at, it's not going to be a late night either way.

This is what they came to see.

Luke Littler looked in trouble at a set and two legs down. He looked likely to slip 2-0 behind.

But he just refuses to lose, this lad. He follows up the 142 with a 120 - single 20, treble 20, double 20 - to break the Humphries throw and level the final at one set apiece.

Image source, PA Media

Oh, he's cooking now. Luke Littler takes out the biggest finish of the final so far, 142 with two treble 20s and double 11.

Superb. The teenager is in the groove - and he hits an early 180 next leg to reinforce it.

The crowd are raring to get behind Luke Littler - and he gives them reason with a 180 that elicits a huge roar from the fans.

Littler slips into double five when aiming for tops - but Humphries cannot punish him and the 16-year-old takes out double 15 to give himself a glimmer of hope in this second set.

Image source, PA Media