Simone Biles recaptured her all-around gymnastics crown on Thursday for her sixth Olympic gold and second in Paris, as a gender eligibility row in boxing shook the Games.
Already considered the greatest gymnast of all time, the American Biles made another piece of history as the first woman to regain the Olympic all-around title, having won it in 2016.
Biles capped another scintillating performance with an electrifying floor routine to Taylor Swift's hit song "Ready for It", her high-flying tumbling bringing the crowd to its feet.
Biles famously withdrew from most of her events in Tokyo three years ago because of a debilitating condition that gymnasts call the "twisties", but instead earning plaudits for speaking openly about her mental health.
Biles led the United States to women's team gold this week, the first chapter of what has been billed as a redemption tour for her and her team-mates.
She could add three more golds in Paris as she competes in the apparatus finals on the vault, floor exercise and balance beam.
Biles won her latest gold with 59.131 points to finish 1.199 ahead of Brazil's Rebeca Andrade with 21-year-old defending champion Sunisa Lee sealing bronze with her floor routine, having trailed in fourth going into the final rotation.
Just as the 27-year-old Biles was pulling off more heroics, Canadian teenager Summer McIntosh stormed to the women's 200m butterfly title in swimming for her third medal of the Paris Olympics, and second gold.
The 17-year-old hit the wall in an Olympic record 2min 03.03sec ahead of America's Regan Smith (2:03.84) and Chinese defending champion Zhang Yufei (2:05.09).
Hungary's Hubert Kos triumphed in the men's 200m backstroke.
Greece's Apostolos Christou, who had led until the final turn, took the silver medal, finishing 0.56sec behind Kos, while Switzerland's Roman Mityukov won bronze.
'Forever tarnished'
However, the sporting action threatened to be overshadowed by a major controversy involving an Algerian boxer who failed a gender eligibility test last year.
Imane Khelif took just 46 seconds to overwhelm her battered and beaten Italian opponent Angela Carini.
Khelif is one of two athletes competing in women's boxing in Paris despite failing to meet the eligibility criteria for the world championships last year.
A distraught Carini refused to shake hands with Khelif after a one-sided fight and the Italian sank to her knees and sobbed in the middle of the ring.
She said: "My nose started dripping (with blood) from the first hit."
The bout sparked an immediate reaction from Italian Prime Minister Giorgia Meloni, who said the fight was "not on an equal footing", while prominent public figures from around the world also weighed in.
Harry Potter author JK Rowling said the Games were "forever tarnished".
Israel's first medals
In other developments, Israel won its first two medals of this Games, with their judokas taking a bronze and a silver.
Peter Paltchik won the first medal, a bronze, in the under-100kg class before Inbar Lanir took a silver medal in the under-78kg final of the women's competition.
Israel's participation in these Games was strongly opposed by the Palestinian delegation because of Israel's offensive in Gaza.
Early Thursday, the Olympics athletics programme kicked off with golds in the 20-kilometre walk for Ecuador and China.
Torrential early rain forced a half-hour postponement to the start of the men's walk, but the clouds parted and Brian Pintado from Ecuador took gold. China's Yang Jiayu dominated the women's race.
The men's golf competition teed off with Japan's Hideki Matsuyama shooting a sparkling eight-under-par opening round to take the lead.
Former Masters champion Matsuyama missed out on a bronze medal in a play-off three years ago on home soil in Tokyo.
But he made a magnificent start to his latest medal bid, rolling in eight birdies to move two shots clear of reigning champion Xander Schauffele at the top of the early leaderboard at Le Golf National.
On the red clay of Roland Garros, British tennis legend Andy Murray was again seeking to stave off retirement in the doubles quarter-finals, following two barely believable wins in previous rounds.