Jamaica and Kenya have a decent lead in this second heat...

blimeyguvn0r: C'mon Simon, at least take it seriously... Red Rum on first leg!? When you had Billy Whizz staring you in the face!!

The second men's 4x400m relay heat is just getting under way.

The women follow. This will be Great Britain's team in that one:

L1: Laviai Nielsen

L2: Amber Anning

L3: Nicole Yeargin

L4: Yemi Mary John

friday_the_12th: India are winning at life this week. First the moon landing and now qualifying for the 4 x 400m relay final

Image source, Getty Images

It's a good job Alex Haydock-Wilson has plenty of hair! The lean forward on the line has got Great Britain through in third.

USA win it. India are second.

Behind Alex Haydock-Wilson is in a photo finish on the line with Botswana for third and fourth...

Image source, Getty Images

USA are pulling clear at the front. India are right up there too.

A good leg from Rio Mitcham gets Great Britain into third with one leg to go.

Dobson gets Great Britain into fourth at halfway.

They need a top three finish to automatically make the final...

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

The most important thing is to stay in contention at this stage.

It's not the best opening leg from Lewis Davey. Charlie Dobson has work to do as he takes the baton on.

Lewis Davey and Rio Mitcham were part of the mixed relay team that won bronze earlier in the championships but this is still a tough ask without Matthew Hudson-Smith.

Davey has baton in hand in lane three as they get under way.

The first track events are coming up very shortly - the men's 4x400m relay heats.

Great Britain, the European champions, are in the first heat with USA and Olympic bronze medallists Botswana

The top three in each heat go through automatically.

I think Simon might have found a problem with my rules...

Simon Ashby: I reckon Red Rum on the first leg, handing over to Mark Wood, then get Lauren Hemp going and on the final leg it's Sarah Storey

Mondo Duplantis has just popped himself over the pole vault barrier with enough space to carry his shopping with him too.

Quite the statement.

There are six jumps each in this final meaning there's a long way to go. He has passed at the next height too.

Image source, Reuters

The decathlon concludes tonight and four men are in contention to win their first World title.

The javelin throw and 1500m are the last two events left in a discipline which sees athletes compete in 10 track and field events over two days.

2022 silver medallist Pierce LePage is currently in pole position with 7477 points.

German Leo Neugebauer is in second 7282 points and 2020 Olympic champion Damian Warner sits in third with 7260 points.

Two-time Commonwealth champion Lindon Victor is lurking close behind with 7214 points in fourth.

Dame Denise Lewis
Athens 2000 Olympic heptathlon gold medallist on BBC TV

Image source, Getty Images

We've seen with Yulimar Rojas in the women's triple jump that when you are hands out favourite, sometimes it can get a little jaded out there.

Temperatures are sapping and draining. It's going to be a long competition.

Armand Duplantis normally comes in at the much later heights so he's going to have to manage his head, his body and his temperament in that competition but he should be unchallenged.

Harry Poole
BBC Sport in Budapest

Could we see Swedish showman Armand Duplantis reset the world record for a seventh time?

What a Saturday night treat that would be for the crowd here. There was an air of expectation as the 23-year-old made his way out to huge cheers.

Here's a reminder of his record-breaking journey so far:

• 6.17m - broke Renaud Lavillenie's world record of 6.16m, which was set in 2014, in February 2020.
• 6.18m - improved his world record in Glasgow the following week.
• 6.19m - cleared at the Belgrade Indoor Meeting in March 2022.
• 6.20m - achieved just 13 days later at the same venue.
• 6.21m - at last year's World Championships, with gold already secured.
• 6.22m - added his most recent one centimetre improvement in France in February.
• 6.23 - pending...

Image source, Getty Images

Great Britain and Northern Ireland's men and women are in 4x100m finals action tonight.

If you were on track, which three sportspeople would you choose to help you win gold?

There are two rules. No track and field athletes allowed and you must pick at least one man and at least one woman.

Kyle Walker is the first shoo-in, right?

Image source, PA Media

We've had confirmation of Great Britain's men's 4x400m relay quartet for tonight.

Matthew Hudson-Smith, the silver medallist from the individual event, is not going to take part. We'll have to see if he comes in for the final given his Achilles injury, if GB even get there.

Leg One: Lewis Davey

Leg Two: Charlie Dobson

Leg Three: Rio Mitcham

Leg Four: Alex Haydock-Wilson