Jamaica’s Elaine Thompson bucked the trend on a huge night for United States women athletes as she became the first woman since Florence Griffith-Joyner at Seoul in 1988 to win the sprint double at the Olympics, winning the 200 metres in 21.78sec after holding off the world champion Dafne Schippers of The Netherlands, who clocked 21.88.
Either side of her victory the US stacked up the medals as Tianna Bartoletta’s late personal best of 7.17 metres prevented compatriot Brittney Reese from retaining her long jump title and then Brianna Rollins led an American clean sweep in the 100m hurdles.
Meanwhile Usain Bolt, winner of his 200m semi-final in 19.78, the second fastest time of the year, will prepare for a final tomorrow night in which his main rival looks like being the former world and Olympic 400m champion LaShawn Merritt following the shock exit of his perennial US rival Justin Gatlin.
And he will be trying to round off his individual Olympic career not only by sealing a third successive 100/200m double, but by lowering his own world record of 19.19 in the longer sprint.
The pity of it that all this drama was played out before something very much less than a full house.
Gatlin, the 34-year-old 100m silver medallist here, could only manage third place in his semi-final in 20.13, while Merritt - who has run 19.74 this season - won his semi in 19.94.
Asked about Gatlin, Bolt commented: "I wasn't truly surprised, I thought he actually made it but I could tell from the 100m he was slowing down."
Looking ahead, he added: "I definitely think I can try for the world record, I definitely feel that.
"I need to run efficiently and get into the straight and run the perfect race.
"If I can run a little more efficiently on the turns. I will be hoping for lane six or seven maybe to be able to run as smooth as I can."
Gatlin added: "My ankle was jammed up and I felt a lot pain through my Achilles so I couldn't really get the job done the way I needed to.”
Schippers, fifth in the 100m final, had complained of an injury in her late preparations for competition here which had almost convinced her to return home.
The powerful former heptathlete nevertheless qualified in good order for the final, and did all she knew to catch the fleet Thompson down the finishing straight after the Jamaican had emerged from the stagger with a clear lead.
"My school motto was 'let the light shine' and I let my light shine tonight,” said Thompson.
"It's a big surprise to me because I have had a hamstring injury.
"You must overcome these things and tonight I am standing here with a gold.
"To beat Dafne Schippers is a hard run.”
Schippers commented: "I came for gold - I was in good form.
"I was getting closer and closer - I felt I was nearly passing her, but then I broke down as well.”
The women’s long jump final was a contest of escalating drama and tension.
Serbia’s Ivana Spanovic took a first round lead with 6.95m that she held until the third round when it was taken over by Bartoletta, who equalled her jump and had a better second effort of 6.94m to her credit.
The lead remained with Bartoletta after the fourth round - and still everyone was waiting for the defending champion to come to life.
Reese missed out on the world title last year after having surgery in 2014, but the five-times world champion’s win at last month’s US trials in a personal best of 7.31m made clear her continuing potential to wipe all opposition out.
In the fifth round, it happened – Reese took the lead with 7.09m.
But the drama had only just begun as Spanovic, now in bronze medal position, responded with a national record of - tantalisingly - 7.08m.
Into the last round we went, and suddenly Bartoletta had regained her lead with 7.17m and Reese had everything to do on her last jump.
After soliciting the crowd’s support by clapping hands over her head, Reese powered down the runway and produced a champion’s response – but at 7.15m it was still two centimetres short of her compatriot’s mark.
A final effort from Spanovic, 7.05m, earned her more credit but confirmed her in bronze position as well as assuring Bartoletta of gold.
Three women over seven metres – an astonishing contest.
"I couldn't really celebrate," said Bartoletta.
"I kept thinking that at any moment someone can jump something huge.
“Then, when I won, I realised that I have to be back in the morning for the relay."
Reese commented: "I'm not disappointed at all.
"I've been through a lot these past two years, emotionally and physically, battling back from surgery."
The women’s 100m hurdles was more clear cut as Rollins, the 2013 world champion, had qualified fastest in 12.47 ahead of compatriot Kristi Castlin, who clocked 12.63and this was how it played out in the final also.
Rollins, smooth and efficient, took gold in 12.48m as Castlin finished runner-up in 12.59 before confirmation – to much whooping – that the third US entrant, Nia Ali, had taken bronze in 12.61.
Afterwards, Castlin dedicated her medal “to victims of gun violence".
How different might it have been if Kendra Harrison, the US hurdler who broke the 26-year-old world record by running 12.20 last month, had managed to qualify from the sudden death US Olympic trials?
We will never know.
Meanwhile another US athlete was having a good day – Ashton Eaton, seeking to become the first decathlete to retain his Olympic title since Britain’s Daley Thompson at Los Angeles in 1984, set himself up nicely by ending the first day with a lead of 121 points over Kai Kazmirek as he assembled 4,621 points, with the German on 4,500 points, 11 ahead of Canada’s Damian Warner.