Postpublished at 20:06 British Summer Time 22 July 2016
Women's 400m
Four Brits involved in this one - Christine Ohuruogu, Anyika Onuora, Seren Bundy-Davies and Emily Diamond.
The women's 400m....is....a...GO.
Summary
Usain Bolt wins 200m in 19.89 seconds; Gemili third
USA's Keni Harrison sets 100m hurdles world record in 12.20 seconds
Porter sixth and Ennis-Hill eighth in hurdles final
France's Jimmy Vicaut wins 100m in 10.03
GB's Laura Muir wins 1500m in new GB record
GB women set national record for 4x100m relay
Johnson-Thompson third in high jump with PB
Postpublished at 20:06 British Summer Time 22 July 2016
Ohuruogu on her waypublished at 20:03 British Summer Time 22 July 2016
Women's 400m (20:05 BST)
Britain's Christine Ohuruogu is coming up in the women's 400m at 20:05 BST.
A gold medalist at Beijing 2008, the 32-year-old picked up a silver here in 2012, finishing behind American Sanya Richards-Ross in the final.
Ohuruogu was forced out of the British Championships in Birmingham last month because of a virus but returns to action tonight, as she prepares for her fourth Olympics.
Image source, Getty ImagesPostpublished at 20:02 British Summer Time 22 July 2016
Aimee Lewis
BBC Sport at the Olympic StadiumThe hospitality section to my left is bustling. Lord Seb Coe is among them, doing what every top banana does, mingling with the crowd - or do they call it networking?
The suited Coe seems to be enjoying himself, as do the rest of the VIPs, sipping expensive bubbly, animately chatting as top-class sport plays out in front of them.
On the track, Katarina Johnson-Thompson is warming up for the high jump. Did the heptathlete notice the roars as Jessica Ennis-Hill produced a season’s best in the 100m hurdles? Who knows.
Get involvedpublished at 19:59 British Summer Time 22 July 2016
#bbcathletics
It may have been four years ago (sob) but we want you to tell us about your favourite memories from London 2012.
Was it Usain Bolt taking three golds? Or the incredible Super Saturday crew?
Let us know via the hashtag #bbcathletics on Twitter.
Getting to know youpublished at 19:58 British Summer Time 22 July 2016
Women's high jump (from 19:55 BST)
British heptathlete Katarina Johnson-Thompson will soon be getting under way in the women's high jump.
Here's three things you might not know about the 23-year-old (apart from the fact she has an excellent name).
Media caption, KJT: My life-changing Pop Idol moment
Postpublished at 19:57 British Summer Time 22 July 2016
Aimee Lewis
BBC SportIt's all gone a bit West Ham United at the Olympic Stadium. With Premier League football come new seats, swanky hospitality and football pictures adorning walls. Not that I'm complaining, I'm a big fan of the cushioned seats in the media section. White leather, too. Naturally.
Image source, BBC Sport at the Olympic StadiumReaction to GB's record-breaking 4x100m winpublished at 19:55 British Summer Time 22 July 2016
Asha Philip: "We came here to show that we can win a medal in Rio and that proves it."
Desiree Henry: "This tells the rest of the world that we are going to Rio intent on winning a medal. I'm so happy with the time. Wow!
Dina Asher-Smith: "To have done that in front of this amazing crowd on our own track is amazing."
Daryll Neita: "We put in the work and got the result."
Desiree Henry was brilliant value in her interview on BBC Red Button. Infectious enthusiasm. But then the quartet did run a national record and a world-leading time.
Image source, ReutersPostpublished at 19:51 British Summer Time 22 July 2016
Women's 100m hurdles heat two
Woooosh. An incredible run from Kendra Harrison in the second heat of the women's 100m hurdles.
The American speeds home in 12:40 to set a stadium record, as Cindy Ofili of Britain finishes fifth.
Unfortunately we won't see Harrison at Rio, as she failed to finish in the top three during qualification trials.
Ennis-Hill through to hurdles finalpublished at 19:48 British Summer Time 22 July 2016
Denise Lewis
Olympic heptathlon gold medallist on BBC TVHer start wasn't brilliant but once she's in her running flow she attacks the hurdles and is so good at the latter part of the race, it keeps her in the game.
It was Ennis-Hill's second fastest time ever...yikes.
Ennis-Hill delighted with fast timepublished at 19:46 British Summer Time 22 July 2016
Women's 100m hurdles heat one
Jessica Ennis-Hill on BBC Red Button: "I didn't expect to make the final but I'm really happy to make it. It's great to be back here. The crowd is amazing and it gives you such a buzz. I'm so happy to have run that time ahead of Rio."
Image source, Getty ImagesEnnis-Hill through to finalpublished at 19:45 British Summer Time 22 July 2016
Women's 100m hurdles heat one
We're looking at the screen for clarification for who's progressed.
Huge cheers as Jessica Ennis-Hill makes it through in third with a 12:76 season's best!
Nia Ali of the USA finishes first in 12.69, with compatriot Brianna Rollins (12:74) in second.
Image caption, Ennis-Hill dips for the line in lane nine
Postpublished at 19:41 British Summer Time 22 July 2016
Women's 100m hurdles heat one
Go! Go! Go! They're out of the blocks in the women's 100m hurdles...
Ennis-Hill in actionpublished at 19:38 British Summer Time 22 July 2016
Women's 100m hurdles (19:40 BST)
There's no heptathlon at the Anniversary Games, but it hasn't stopped Olympic champion Jessica Ennis-Hill getting involved.
The Briton is warming up now for the 100m hurdles - her strongest discipline - with the heats starting at 19:40 BST. She's up against fellow Team GB runner Tiffany Porter, while three of the best American hurdlers are also involved.
The final is at 21:15 BST
Ennis-Hill is then back for more on Saturday, as she competes in the long jump against compatriot and fellow multi-events star Katarina Johnson-Thompson.
Image source, Getty ImagesPostpublished at 19:35 British Summer Time 22 July 2016
Andrew Cotter
BBC athletics commentatorWhat a way to kick-start the evening. A tremendous performance from the team with a new national record.
Britain's A team win women's 4x100mpublished at 19:33 British Summer Time 22 July 2016
A British record for this foursome at 41:82.
Solid changeovers throughout, and after the Netherlands folded early doors, Daryll Neita drove home with ease.
GB's B team finished fourth as well. A decent start to proceedings in front of a home crowd.
Postpublished at 19:31 British Summer Time 22 July 2016
We're off in the 4x100m women's relay!
GB's A Team are in lane two, with their compatriots going in lane four.
#Tooexcitedpublished at 19:30 British Summer Time 22 July 2016
London Anniversary Games 2016
Britain's Holly Bradshaw has arrived at the Olympic Stadium to watch tonight's action.
The pole vaulter will take to the track on Saturday for her event.
Double teamingpublished at 19:26 British Summer Time 22 July 2016
4x100m women's relay
Warm-up commences for the 4x100m women's relay.
There's not one but two British teams involved, handily marked A and B.
In Great Britain 'A' is Asha Philip, Desiree Henry, Dina Asher-Smith and Daryll Neita.
In the B squad is Louise Bloor, Bianca Williams, Rachel Johncock and Jacinda Papps.
They are up against teams from Poland, Switzerland, Jamaica, Netherlands, Brazil, France and Canada.
Postpublished at 19:23 British Summer Time 22 July 2016
Steve Cram
BBC athletics commentator on BBC TwoAthletes still talk about London 2012 because it's a special place for them. It's a place where they feel they can run well. And let's hope that Usain Bolt can shine tonight.
Race daypublished at 19:22 British Summer Time 22 July 2016
London Anniversary Games 2016
Here he is, the big man, preparing for race day.
Usain Bolt posted this on Twitter earlier, and he's currently being driven round the track at the Olympic Stadium being introduced to the expectant crowd.
I found out today Usain also has his own set of emojis.
He really is living the dream.