A sprint finish in the first women's 1500m semi-final... The top five go through automatically... Sifan Hassan of the Netherlands crosses the line first, with Ethiopia's Dawit Seyaum behind her in second. 

Abeba Aregawi, Shannon Rowbury and Malika Akkaoui through too. 

Minions, house fires, big caves... 

Kelly Sotherton
Former British heptathlete on BBC Radio 5 live

"If Gatlin wins, where does the sport go from here? Everyone in the general public thinks every athlete is taking drugs. I really want a Bolt win to clarify that you can win being clean."

Who will be crowned the 100m world champion? The bookies' predict victory for Justin Gatlin, while many a heart is hoping for a Usain Bolt victory. It's good versus bad, which is why this race is so compelling. 

Why not vote for your predicted winner in our vote? There are nine men to choose from (click on the tab if you're on a mobile).

There's 30 minutes or so until today's finale, the men's 100m. The usual suspects will be competing. Olympic and world champion Usain Bolt won his semi-final, but only just. Here's what happened...

In the final men's 800m semi-final Ferguson Rotich and Amel Tuka crossed the line together, but it's Bosnia-Herzegovina's Tuka who is declared the winner in 1:44.84. 

There's no Nijel Amos in the final so does than make David Rudisha the favourite? 

Image source, Getty Images

Sue Cafolla:  What an athlete! A truly outstanding performance from @J_Ennis, external to win gold

Jane:  Poor KJT really feel for her. Hope she picks herself up!! Go Jessica Ennis-Hill.

Dan Pickering:  Just an Idea, don't use the athletes name if they have served a doping ban. Just use A N Other and don't interview them.

Where to look and what to report on first? There's plenty happening in the Bird's Nest. America's Joe Kovacs has won shot put gold with a magnificent 21.93m effort. 

Germany's David Storl (21.74m) won silver Jamaica's O'Dayne Richards in bronze with a national record throw of 21.69m. 

More from heptathlon champion Jessica Ennis-Hill on BBC Two:

"I'm lost for words. I can't believe I'm here. This time last year I'd just had my son and now I'm here competing. 

"It was a massive surprise to be here. There were doubts before the Anniversary Games but performing in London showed me I was making progress. If I'd come away with a bronze I'd have been so happy, so to win gold is unbelievable.

"This has been the hardest year ever. There were different pressures going into London 2012, but here juggling all my mummy duties has been even harder.

"I want to thank everyone for their help and sacrifices in helping me get back to being the athlete I was."

Aaron:  Bolt to break the world record and get 9.55, Gatlin second in 9.65 and Asafa Powell third in 9.87.

Tony McDonald: @J_Ennis, external You are an absolute legend!! My wife can't believe you can do that a year after having a babe! Enjoy!#jess#legend.

Clare Swift:  Hate to say it but I think Gatlin is going to win this #bbcathletics, external#comeonbolt, external#100m, external

Heptathlon champion Jessica Ennis-Hill has finished her celebratory lap and has found Phil Jones. 

"I was so sad for her, but she's got time on her hands," says Ennis-Hill of her rival Katarina Johnson-Thompson, who fouled out of the long jump. 

But of her own triumph, the world champion says: "We've all been on a huge journey this year. My family are incredibly, I have to thank my husband for all his support and my little boy. I've got an incredible team around me."

Commonwealth champion Nijel Amos, incredibly, was third which means the Olympic silver medalist, and Rudisha's nemesis during the last 12 months, will not be competing in the final. My oh my. The man from Botswana was pushed out by Qatar's Musaeb Abdulrahman Balla. 

Image source, EPA

Olympic champion David Rudisha is competing in the second men's 800m semi-finals. A relative slow first lap, the bell rings and the men up the ante...

Rudisha still out in front coming into thefinal bend, extends his stride and wins in an unofficial 1:47.71..

British team-mate Ashleigh Nelson seems to be enjoying Jessica Ennis-Hill's heptathlon success.

While we were absorbed in Jessica Ennis-Hill triumphant celebrations, the first of the men's 800m semi-finals was taking place and what a four-man finish it was. 

Who went through? It's initially difficult to tell - rice paper separating a trio of runners - but it was a victory for Poland's Adam Kszczot, with Kenya's Alfred Kipketer second. 

Where was Ethiopia's Mohammed Aman? The defending champion third so he must wait to find out if he gets one of the fastest losers spots.

Michael Johnson
BBC Sport athletics expert & 400m world record holder

"This will be a great springboard towards Rio for Jess, and a fantastic confidence booster for her as an athlete. Already looking towards next year, It puts a lot of pressure on her rivals."

Image source, Getty Images