US sprinters laid down an Olympic relay gauntlet to their rivals on Thursday ahead of a possible Noah Lyles sprint double, while marathon swimmers took the plunge into the River Seine.
As the Paris Games builds to a crescendo this weekend, LeBron James leads his dream team of US superstars into a semifinal against a Serbia powered by Nikola Jokic, the NBA's three-time most valuable player.
Before then, the American men and women both powered through their 4x100m relay heats to warn off any rivals aiming to challenge their dominance.
Stung by having to settle for 100m silver, Sha'Carri Richardson ran her anchor leg in an eye-popping 9.99sec to see the women home while the men could afford to leave out Lyles and still cruise to victory.
Lyles won 100m gold in a dramatic photo-finish at the weekend and will undoubtedly be part of the team for the final, but for now his priority is Thursday night's 200m.
"I spent years working on the 100m, but the 200 is where it's at. This is where I get to show my speed and endurance and my top-end speed," said Lyles.
"This is where I get to show I'm stronger than everybody else."
The American will face competition from teammates Kenny Bednarek and Erriyon Knighton, as well as 21-year-old Botswanan Letsile Tebogo, who beat him in the semifinal.
'CLEAR FAVOURITE'
In what could be the race of the Games, the two fastest women in history over the 400m hurdles clash on the lilac track of the Stade de France.
Reigning champion Sydney McLaughlin-Levrone from the United States and Dutchwoman Femke Bol go head-to-head in a mouth-watering final.
"I am looking forward to racing Sydney. That will push us both. Sydney is the clear favourite, but I will be ready for it," said Bol ahead of the race.
Bol already has one gold after running an extraordinary anchor leg to bring the Dutch to victory in the 4x400 mixed relay.
But McLaughlin-Levrone is the world record holder and defending Olympic champion in the 400m hurdles. Bol is plotting revenge after finishing third in Tokyo.
In a packed athletics programme Thursday, three-time world champion Grant Holloway from the US hopes to go one better than the silver he won in the men's 110m hurdles three years ago.
'DO IT FOR HIM'
Earlier Thursday, 24 women dived into the River Seine, which was deemed clean enough for competition, for the 10-kilometre swim through the heart of the city.
Sharon van Rouwendaal from the Netherlands won a gruelling battle against her competitors and a strong current in 2hr 3min 34sec, devoting her gold to the memory of her pet dog, Rio, who died in May.
"Swimming is my everything, but so was he... My father said: 'swim one more time and do it for him. And that's what I did'," she added.
Water quality in the Seine has been in the spotlight during the Olympics despite a 1.4-billion-euro ($1.5-billion) effort to improve sewerage and water treatment.
Organisers have been forced to scrap several training sessions and postpone the men's individual triathlon after assessing the water to be too dirty to swim in.
'SUPER POSITIVE'
As the basketball tournament approaches the business end, the US and Serbia face each other for the third time in as many weeks, after a pool match and a pre-Olympics warm-up.
The US have won both previous times by 26 points but coach Steve Kerr is taking nothing for granted, saying: "We can't get lulled to sleep because we beat them twice."
Hosts France, led by towering San Antonio Spurs star Victor Wembanyama, play World Cup holders Germany in the first semifinal.
France were also in contention in the women's golf tournament with Celine Boutier taking a three-shot lead into the second round.
But she dropped four shots in her second round, handing the lead to Switzerland's Morgane Metraux who shot a superb six-under-par round to send her three shots clear on eight under.
In men's hockey, world No 1 Netherlands take on world champions Germany, hoping to write the first chapter of a golden double, as the Dutch women face China for gold on Friday.
Former hockey powerhouse India clinched bronze with a nail-biting 2-1 win over Spain.