Matthew Hudson-Smith was forced to settle for silver in the final of the 400m on Wednesday after Quincy Hall hunted the Brit down with one metre to go.
The British favourite led around the final bend and towards the finish but American Hall pipped him to the Olympic title. Muzala Samukonga of Zambia finished third.
Just 0.04 separated first and second with Samukonga 0.3 further back.
Hudson-Smith has been on a rollercoaster journey to these Olympics with his mental health and previously revealed that he had made an attempt on his own life.
But he has since won a world silver and a European gold, and now an Olympic silver.
The 29-year-old was bidding to become the first British man to win an Olympic 400m title since Eric Liddell in Paris in 1924, the Games which inspired the iconic Chariots of Fire.
He does, though, become the first British man to win a 400m silver since Roger Black in 1996.
Elsewhere at Paris 2024
Elsewhere in the Stade de France last night Amber Anning dipped below 49.5 seconds as she qualified for Friday’s 400m women’s final.
The Brit has been a shining star of 400m running, alongside Hudson-Smith, and will have an outside shot at a medal on Friday.
On Thursday Katarina Johnson-Thompson gets her heptathlon bid underway as she looks to take on rival Nafissatou Thiam over the next two days.
Team GB’s men and women get their 4x100m relay campaigns underway having won a bronze medal in the 4x400m mixed relay on the opening day of track and field at the national stadium of France.
Team GB’s women set a national record earlier this year in London but at the same meet the men failed to get the baton around the track.
There will be no British interest in the men’s 200m final tonight but Noah Lyles will be bidding to go for the sprint double after winning the 100m earlier in the week.
And in what some are billing the race of the meet, Femke Bol and Sydney McLaughlin-Levrone go head-to-head in the women’s 400m hurdles final.