Bolt (19.55) wins 200m gold from Gatlin in silver (19.74)
GB's Zharnel Hughes fifth
USA's Allyson Felix wins 400m for ninth world title
Christine Ohuruogu eighth in 400m
GB's Sophie Hitchon fourth in hammer final
Asher-Smith wins 200m semi in 22.12
GB's Oskan-Clarke wins 800m semi-final
Men's triple jump final (12:10 BST)
As we've already said, but perhaps it's worth saying again, Olympic champion Christian Taylor of the United States and Pedro Pablo Pichardo of Cuba have both gone over the 18m mark this season.
Briton Jonathan Edwards' (@JDE66) world record, set at the 1995 Worlds, is 18.29m.
The men's triple jump final is about to begin and there's plenty of talk of a certain world record being broken. Jonathan Edwards shuffling a little uneasy in the BBC Radio 5 live seat...
Image source, BBC SportRussia's Sergey Shubenkov wins the first 110m semi-final in 13.09, just as the headline says.
His fellow automatic qualifier is Jamaica's Hansle Parchment (13.16).
(The top two in each semi-final, plus the two fastest overall losers, will go through.)
BBC Radio 5 live is, well, live with Darren Campbell and co talking us through the day's action.
Mr Campbell has just tweeted an interesting picture; put 10 barriers on the track and take the start back a touch and it could be the view for the 110m hurdles?
The men's 110m hurdles semi-finals is the first track event of the day and the barrier negotiators are on the start line, waiting to be called into action. No Colin Jackson here, not quite sure what happened to him, but European champion Sergey Shubenkov is in the first semi-final.
Gatlin debate
Alice Stainer: If one of them were British it might be different. @jarrowarrow, external has a passion for the sport & should be allowed to express it.
Jason Sherratt: Gatlin has no right to complain how the media treat him. He's guilty and has to ride the storm. He's lucky to be there!
Tim Fry: It's not Gatlin's fault he's been treated lightly. Seb Coe needs to bring WADA and the IAAF together and enforce longer bans.
The women's hammer final will begin in a few minutes and it features Britain's Sophie Hitchon.
Poland's Anita Wlodarczyk is the overwhelming favourite, though, as she's already broken the world record this year and qualified in top spot with a 75.01m effort.
Image source, BBC SportSouth Africa's Wayde van Niekerk is standing! The 400m world champion has recovered from yesterday's lung-busting, leg-ruiner of a 43.48-second win and is standing on top of the podium with a gold medal around his neck.
The world champion looking a tad self-conscious, though, as he sings the national anthem. Sing it loud, sing it proud, Wayde.
Image source, BBC SportWhat to focus on next after that enthralling Gatlin debate?
The men's triple jump final begins at 12:10 BST. It's an event Cuba's Pedro Pablo Pichardo and America's Christian Taylor are pushing each other to their limits.
Both are consistent, both will be vying for triple jump gold and both jumped over 18m earlier this year for the first time.
Could they go near Jonathan Edwards' 20-year-old 18.29m world record? They still have quite a bit to do. Taylor's personal best is still 23cm beyond Edwards' mark, while Pichardo's personal best 18.08m is 21cm short.
Image source, BBC SportJase Ives: Arrogant, unsincere, non contrite. Victimised?? Do me a favour. Gatlin and all other cheats deserve no credit.
Tina Malcolm: #Michaeljohnson, external yet again you command the commentary with knowledge & authority. BBC hire him FT
Dom Breslin: Gatlin and his agent need a reality check. Caught cheating not once but twice. I'm proud to celebrate when cheats lose.
James Layton-Hill: Engrossed on the Gatlin debate. He cheated and has done nothing to right his wrongs
Ben King: Michael Johnson telling it how it is.....'I don't like Gatlin, I never have'. I love to see honesty from former athletes
Don Dreper: Those 15 minutes is for me, what sports broadcasting should be. No hiding. No easy narratives. Strong, intelligent discussion
More quotes from Justin Gatlin's agent, Renaldo Nehemiah, who tells BBC Sport: "I'm not defending Justin Gatlin. If people cannot forgive this young man why do you let him back into the sport?
"To me, it's personal. Steve Cram's comments were very personal. BBC radio (5 live) to see video of them jumping up and down celebrating is unprofessional."
Image source, Getty ImagesMore comments from Justin Gatlin's agent, Renaldo Nehemiah, who is unhappy with the BBC's coverage of the American sprinter.
"When he lost everyone got enjoyment out of that. To see people in the BBC celebrating, it's not objective," said Nehemiah.
"I know Steve Cram. But him saying Bolt was 'saving the sport' and those kind of comments, we're better than that. You have to be better reporters. Behind closed doors feel how you feel, but when you have millions of people hanging on your every word, that's when I start to worry."
Michael Johnson
400m world record holder on BBC TV
Quote MessageWe have also been talking about how fast he has been running all week and how incredible his form and technique is, but we have to talk about all of what's going on.
Here is what Renaldo Nehemiah, Justin Gatlin's agent, told BBC Sport: "I don't have any problem with people having an opinion but I do have a problem when individuals inside the IAAF have spoken about their unease in having him come back into the sport.
"I also have no problem with the media asking tough questions, but I do have problems when it is not balanced or fair.
"Sixty-six other people have had doping offences, there were four of them in this race. But I understand why Justin Gatlin was being talked about. He has been carrying all the resentment towards him from people who have no idea who is."
Image source, APMichael Johnson
400m world record holder on BBC TV
Quote MessageJustin hasn't given any apology, shown contrition or tried to understand why people feel the way they do about him. The excuse he gave for his second positive test is hard for anyone to buy - he has to understand that, and then he might understand how we feel.
Steve Cram
BBC athletics commentator
Quote MessageI don't think we need to be neutral as commentators, we need strong opinions because of what's happening in the sport. I know others have been banned but Gatlin is a star, he was supposed to be one of the heroes of the sport.
There's been an absorbing 10-minute period of television on BBC Two and online which is well-worth watching if you missed it.
Justin Gatlin's agent Renaldo Nehemiah criticises the British media, and Steve Cram's commentary of the 100m final in particular.
Steve Cram, in return, gives his side of the argument, saying commentators need "strong opinions".
Everyone loves a medal table and Britain are still second thanks to gold medals from Mo Farah, Jessica Ennis-Hill and Greg Rutherford. But coming in at number one are the non-movers Keyna, who are top of the pops.
There's a schedule to follow and follow it we will do today. Four gold medals to be won today, drama to unfold, here are the events coming up:
Image source, BBC Sport