While we wait for the women's 4x400m to start, have a watch of this.

And, if we have the time, watch it again.

Steve Backley
Two-time world and Olympic javelin silver medallist on BBC Two

Gerson Balde has done something I don't think anybody saw coming!

His coach certainly didn't. They maybe hoped for it, but goodness gracious me that's shaken things up somewhat.

Wakey, wakey chaps - you've got a new leader! This is a brilliant end to the competition.

Dame Jessica Ennis-Hill
Three-time world heptathlon champion on BBC Two

You have to put Keely Hodgkinson on that anchor leg.

She has the speed and she won't need to do too much warming up after claiming her fantastic gold medal, so I think it's a fantastic position for her to be in.

Let's hope she brings home another medal...

Image source, Getty Images

With one round to go, Mattia Furlani, the reigning indoor and outdoor world champion, topped the standings of the men's long jump.

The Italian hit 8.39m on his fifth attempt, leading Bozhidar Saraboyukov of Bulgaria (8.31m) and Cuba's Jorge A. Hodelin (8.26m).

But hold on, what's this?

Portugal's Gerson Balde, last to go in the final round, jumps 8.46m to take the lead!

It's a world leading distance for the year - he'd jumped a best of 8.19m with his five previous attempts.

Greg Rutherford
Former world and Olympic long jump champion on BBC Two

Dina Asher-Smith mentioned yesterday that she was trying something new with her new coach, so this is brilliant to see.

If this works out, it will be an absolute stroke of genius. We know how quick she is so this could be brilliant.

Dame Jessica Ennis-Hill
Three-time world heptathlon champion on BBC Two

I would love to talk about Dina Asher-Smith's inclusion, but it's quite a surprise for all of us I think!

We aren't used to seeing her take part in a 4x400m, especially not indoors as well, in fact I don't think she's ever competed indoors in this event.

It's a big difference to the 60m event. She is obviously in great 60m running-shape but it will be a big change in distance for her.

Steve Cram
1983 1500m champion on BBC Two

I'm not even sure how stretched Khaleb McRae was, but he ran 44.65 in the last leg.

When you've got the ability he has, as the world-record holder, he probably didn't need to use up everything he had to keep Team USA in front.

He ran a very controlled last leg. They've set a new championship world record - and a lot of that is to do with his finish.

Here's how the GB team reached the women's 4x400m final.

They'll be fielding an altered line-up, with Dina Asher-Smith (second leg) and Keely Hodgkinson (fourth) coming in alongside Tess McHugh (first) and Louisa Stoney (third).

Jazmine Moss and Poppy Malik, who ran the second and third legs in the heats, drop out, while Stoney and McHugh shift from the first and fourth legs respectively.

USA's gold in the men's 4x400m nudges them back to the top of the medal table ahead of Britain.

If GB win the women's 4x400m relay, they will claim top spot in these championships.

They couldn't, could they?

Look at them there. Pure class.

Image source, Getty Images

Image source, Getty Images

Midway through the event, it is a battle between Belgium and USA for the gold.

First, it's the turn of the men. No GB interest here.

Jamaica, USA, Hungary, Portugal, Netherlands and Belgium are the competing teams.

Folks, the final event of these championships will be must-see.

Not only will Keely Hodgkinson be racing in the women's 4x400m relay for GB - we have just had news that Dina Asher-Smith will be competing too.

It's an all-star show!

Greg Rutherford
Former world and Olympic long jump champion on BBC Two

Devynne Charlton, that was absolutely mind-blowing!

I'm just in awe of what we've just witnessed. To be able to stumble like that and lose the amount of time she would've done, yet still equal the world record is just mind-blowing. It just shows the level of talent.

If you're ever uncertain of the quality in this sport, remind yourself of this.

Image source, Getty Images

Colin Jackson
Two-time world 110m hurdles champion on BBC Two

I'm absolutely speechless!

The stumble Devynne Charlton did coming out of the blocks and going into that first hurdle cost her more than five-hundredths of a second, so I think she was running at a 7.58 pace! That is just outrageously fast.

She is the queen of indoor sprint hurdling, by far.

Great Britain's Molly Caudery, who won gold in the women's pole vault, speaking on BBC Two: "It's a big relief. It feels so nice! I don't know what more to say. I'm not sure if I'm showing emotion or what because I've actually got a really bad cold, believe it or not! I woke up this morning and I didn't know if I would be able to jump, but obviously I could!

"Honestly, six weeks ago I couldn't even get off the ground. I was in a really dark place, so to come here and do this today means more than anybody in the world knows. After Paris and Tokyo and last year, it is just a relief.

"It is all about my team and everyone is here today supporting me, they were right there in the crowd. After every jump I looked up and saw their faces. It's definitely not just been me, so a huge thank you to everyone - my coach, my family and my fiance.

"I cleared everything first time to 4.80m, but up to 4.70m I just wanted to put out a solid performance. I wasn't even jumping back in January so it's been a really quick turnaround. It's been really amazing. It felt so good to clear 4.85m. I haven't enjoyed jumping this much in a long time, so to feel that again was just the best."

Image source, Getty Images

Dame Jessica Ennis-Hill
Three-time world heptathlon champion on BBC Two

It really does feel sweeter than two years ago!

When you're a young athlete and you're having success, it really does take something massive to stop you in your tracks and Molly Caudery has had that.

It might have helped her really realise what she wants to go on and achieve. To be able to turn it around and become world champion again is really phenomenal.

This is officially Britain's most successful World Indoor Championships of all time.

GB's best previous gold haul was three in 1999. They have won four in Torun.