A Japanese skateboarder claimed a piece of Olympic history as the host nation enjoyed a gold rush at the Tokyo Games on Sunday, while France inflicted the first defeat on a men's USA basketball team since Athens 2004.
There were 18 gold medals up for grabs, including the first ever in skateboarding, one of several new sports introduced in Tokyo in a bid to attract younger fans.
The 22-year-old, who grew up just a stone's throw from the Olympic venue, landed three huge tricks in a row to eclipse American favourite Nyjah Huston, who finished seventh.
"This is special because it was held in Koto City, where I was born," said Horigome.
Horigome's victory was one of four golds Japan won on Sunday to take the host nation to second in the medals table behind China.
The haul included brother and sister Uta and Hifumi Abe both winning Olympic titles within an hour of each other.
Uta Abe was first to strike gold in the women's under-52kg category, beating Amandine Buchard of France.
Earlier, unheralded swimmer Yui Ohashi had sparked the Japan gold spree in an action-packed morning session at the pool.
Ohashi powered to victory in the women's 400 individual medley, toppling Hungary's defending champion Katinka Hosszu.
"I swam believing in myself. I really did not think of winning the gold," said Ohashi.
Tunisian teenager Ahmed Hafnaoui pulled off the day's biggest swimming surprise by winning the men's 400m freestyle.
The 18-year-old had only qualified eighth-fastest for the final but produced a devastating late burst to win in 3min 43.36sec, overhauling Australian Jack McLoughlin.
It was just Tunisia's third gold ever in swimming. The other swimming medals were split between the US and Australia, with Chase Kalisz winning the 400m medley and Australia taking gold in the women's 4x100m freestyle relay in a world record 3:29.69.
Austrian mathematician Anna Kiesenhofer claimed a surprise victory in the women's cycling road race, which ended in bizarre fashion with Dutch veteran Annemiek van Vleuten crossing the line mistakenly thinking she had won.
Van Vleuten was oblivious to the fact that Kiesenhofer had broken away from the peloton to take gold.
Elsewhere on Sunday, a century-long wait to see surfing at the Olympics came to an end at Tsurigasaki Surfing Beach.
It marked the culmination of efforts to get surfing added to the Olympic programme dating back more than 100 years.
The spectre of Covid-19 meanwhile continued to stalk the Olympics, with the men's golf tournament upended by two high-profile withdrawals.
World number one Jon Rahm was ruled out after returning a positive test -- his second Covid-19 positive in two months -- while Bryson DeChambeau also saw his Olympic hopes end with a positive case.
In gymnastics, US superstar and defending champion Simone Biles produced a rusty performance in qualifying, with several uncharacteristic mistakes in a near-empty arena.