The second day of athletics action brought golds for Elaine Thompson, Nafissatou Thiam, Mo Farah, Jeff Henderson and Christoph Harting.
Shelly-Ann Fraser-Pryce's eight-year reign as Olympic 100 metre champion came to an end on Saturday as fellow Jamaican Elaine Thompson surged to gold.
Thompson was the class of the field in a final that had looked tough to call, a winning time of 10.71 seconds only marginally outside her world-leading effort in 2016.
Fraser-Pryce (10.86secs) had to settle for third behind American Tori Bowie (10.83), with Dafne Schippers and English Gardner missing out on the medals.
There was a major shock in the heptathlon as Jessica Ennis-Hill - the champion in 2012 - finished second to an inspired Nafissatou Thiam of Belgium, who set a host of personal bests and prevailed despite her main rival making up significant ground in the 800 metre finale.
Mo Farah yet again rose to the big occasion, retaining the 10,000m title he won at London 2012. Farah, who did the 5000m and 10,000m double four years ago, suffered a fall midway through Saturday's race, but refused to let the stumble affect him as he beat Paul Tanui of Kenya with a trademark sprint finish.
The men's long jump was won by Jeff Henderson, the American pipping South Africa's Luvo Manyonga by one centimetre as 2012 champion Greg Rutherford finished third.
Jarrion Lawson looked to have threatened Henderson with his final jump, but he had in fact brushed the sand with a trailing arm and had to settle for fourth.
Reigning champion Kirani James was the fastest qualifier for the men's 400m final, ahead of USA's LaShawn Merritt, with a season's best time of 44.02secs, while David Rudisha breezed into the final of the 800m, which he won four years ago.
Earlier on Saturday, Christoph Harting of Germany succeeded brother Robert as the men's Olympic discus champion, while Usain Bolt was slower than arch rival Justin Gatlin in the first round of the men's 100m.
Ennis-Hill put up an admirable defence of her heptathlon crown, but it was not enough as Thiam ascended to stardom with a host of outstanding performances. And at the age of 21, the new champion's best days could well lie ahead of her.
Courtesy of his third Olympic gold medal, distance-running king Farah now stands alone among British track athletes.
QUOTES OF THE DAY
"A gold medal is like a new-born baby. It's just lovely. My mum can't be here, she has Alzheimer's. When I place that medal in her hands, I'll be crying," - an emotional Henderson delights in his long jump triumph.
"It's crazy. I wasn't expecting that - maybe top eight, but not the gold," - Thiam appears as surprised as anyone by her heptathlon victory.
"I felt kind of slow. I'm not used to running this early [in the day] at any championship," Bolt reflects on his underwhelming performance in the men's 100m heats.
The blue-riband event of the Olympic Games - the men's 100m final - takes place on Sunday at 22:25 local time. The women's marathon and triple jump titles will also be decided on Sunday, together with the men's 400m final.