Heartbroken Adam Gemili admitted his World Championships agony hurts more than his Olympics nightmare.
The 25-year-old, who celebrates his birthday on Sunday, clocked 20.03 seconds in Tuesday night's 200m final to come fourth in Doha.
It was not enough to reach the podium as the United States' Noah Lyles took the title in 19.83 secs with Canada's Andre De Grasse second and Alex Quinonez of Ecuador in third.
It echoed Gemili's Olympic hurt when he missed out on a bronze medal by three thousandths of a second in Rio in 2016.
The Great Britain sprinter, who can still help defend the 4x100m title, said: "It's the same, if not worse than that feeling after Rio because of the story behind it, where I've come from after injuries and being written off completely.
"I had it and lost it. I ran like such an amateur, in the one race I needed to get it right and I felt it was there for the taking – I let it slip through my fingers.
"I feel like I've let so many people down. I didn't even run sub-20, that's how bad it was.
"Fourth is the same as eighth, the same as 16th. Unless you're on the podium, who cares?"
Earlier, Great Britain team-mate Dina Asher-Smith underlined her favourite tag by powering through to the 200m final at the World Championships.
The 23-year-old clocked 21.16 seconds – the fastest time of the night – to comfortably win her semi-final in Doha.
Asher-Smith, who holds the British record in the 200m after her European Championships victory in Berlin last year, is expected to take the title on Wednesday.
Major rivals including defending champions Dafne Schippers and the Ivory Coast's Marie-Josee Ta Lou have pulled out injured.
New 100m world champion Shelly-Ann Fraser-Pryce is not running while Nigeria's Blessing Okagbare was disqualified in the heats and reigning Olympic champion Elaine Thompson also withdrew.
Asher-Smith is looking to add to the 100m silver she claimed on Sunday after setting a new British record of 10.83secs.
Beth Dobbin and Jodie Williams both failed to reach the final at the Khalifa International Stadium.
Meanwhile, European 400m champion, Matthew Hudson-Smith, came off the track in a wheelchair after pulling up 20m into the first heat with a hamstring issue.
The 24-year-old has suffered hamstring injury problems this year but team-mate Rabah Yousif automatically reached the semi-finals in 45.40s.
"I gave it my heart and soul. I feel like I could have set it up a little bit better but I definitely can improve for the next round," said Yousif.
Jess Turner and Meghan Beesley also reached Wednesday's 400m hurdles semi-finals while Nick Miller qualified for the hammer final with Zak Seddon through to the 3000m steeplechase final.
Laviai Nielsen and Emily Diamond missed out on the 400m final.
The USA's Donavan Brazier, who trains at the Nike Oregon Project run by Alberto Salazar, won the 800m title.
Salazar, Sir Mo Farah's former coach – although there is no suggestion of wrongdoing by Farah – was given a four-year ban for doping violations on Tuesday.
He was stripped of his accreditation for the World Championships by the IAAF and could not have any contact with his athletes.