Great Britain's Dina Asher-Smith and Daryll Neita finished within three-hundredths of a second of making the Olympic 200m podium as Gabby Thomas stormed to gold.
American Thomas, installed as favourite following the pre-competition withdrawal of Jamaica's world champion Shericka Jackson, dominated the final to win in 21.83 seconds.
Neita, who also missed out on a 100m bronze by four-hundredths of a second on Saturday, and Asher-Smith were each hoping to become the first British woman to make an Olympic sprint podium for 64 years.
But Asher-Smith finished fourth in 22.22 and Neita crossed the line fifth in 22.23, behind runner-up Julien Alfred (22.08) and American bronze medallist Brittany Brown (22.20).
Thomas had to settle for world silver behind Jackson last year, having taken Olympic bronze in Tokyo.
But coming in as the fastest woman this year, and in the absence of her main rival, the 27-year-old unleashed a triumphant roar across the line and held her hands on her head in disbelief after seizing her moment.
"I've envisioned this race over and over in my head so many times, as I do with every race, and that's how I win races," said Thomas. "But I did not expect to feel how I felt when I crossed that line.
"I couldn't believe it. I never would have imagined in my wildest dreams that I would become an Olympic gold medallist. It was the happiest moment of my life."
It was a second Games medal for runner-up Alfred after the 23-year-old had dominated the 100m final to make history as St Lucia's first Olympic medallist.
Behind her was Brown, 29, as she clinched her second global medal – and first since winning world 200m silver behind Asher-Smith in 2019.
Neita, 27, had made no secret of her determination to end her wait for an individual global medal in Paris - and she could not have gone much closer to achieving that.
Such are the fine margins in global sprint finals, she has finished a combined 0.07 seconds away from medals in the Olympic 100m and 200m.
Having made five global podiums as part of the women's 4x100m relay squad, Neita has made impressive progress since reaching – but finishing last - in the Olympic 100m final in Tokyo three years ago.
"All in all it has been a fantastic Olympic Games for me," Neita told BBC Sport. "I am a double finalist. Fourth place in the 100m by a couple of hundredths and [almost] the same here. I know my time is coming, I have to be a little bit more patient.
"I gave it my all tonight. I'm proud of myself but I really wanted to leave here with an individual medal and I am just hungry."
It is to the relay where Neita's attention now turns, alongside team-mate Asher-Smith.
Five years have passed since Asher-Smith, at the age of 23, realised her dazzling potential by becoming the first British woman to win a major global sprint title in this event at the 2019 World Championships.
In pursuit of a first Olympic medal, three years after being left in tears when she missed out on the 100m final in Tokyo, the 28-year-old was bitterly disappointed to fall short once again over that distance in Paris.
But Asher-Smith ensured a positive end to her individual campaign as she brushed off that setback to produce a strong 200m showing.
"I feel good. It has been a long week and I am proud of that performance," she said.
"It was a really strong field, all the girls between them had so many strengths. So many good bend runners, so many amazing finishers and I was really proud that I held my own."
Team GB's Matthew Hudson-Smith set up his opportunity to race for Olympic 400m gold by cruising to victory in a high-quality semi-final.
With three of the six fastest men in the world this year in the same line-up, world silver medallist Hudson-Smith obliterated his competition and eased down before crossing the line in 44.07.
However, team-mate Charlie Dobson, making his Olympic debut, missed out on the qualifying positions as he clocked 44.48 for fourth in his race.
Grenada's Kirani James, a three-time Olympic medallist in the event, posted the fastest time of the round in 43.78.
The men's 400m final takes place at 20.20 BST on Wednesday.
Jacob Fincham-Dukes finished fifth in the men's long jump final on his Olympic debut.
The 27-year-old produced a best leap of 8.14m as Greece's Miltiadis Tentoglou retained his Olympic title by jumping 8.48m.
Fellow Briton Elizabeth Bird was seventh in the women's 3,000m steeplechase final, which saw gold go to Winfred Yavi, of Bahrain.
Lina Nielsen suffered heartbreak in the women's 400m hurdles semi-finals as she fell after clipping the final barrier.
Team-mate Jessie Knight also failed to qualify, finishing fifth in her semi-final.
But American defending champion Sydney McLaughlin-Levrone (52.13) and world champion Femke Bol (52.57), of the Netherlands, won their races to qualify as the two fastest athletes for Thursday's gold-medal showdown.
