Keegan Palmer of Australia won his second consecutive Olympic men's park skateboard title with some spectacular moves on Wednesday, while women's golf star Nelly Korda made an error-ridden start to her title defence.
On the track later, Matt Hudson-Smith takes on a fast field in the 400 metres as he attempts to become Britain's first Olympic champion at the distance in 100 years.
All eyes at the Place de la Concorde venue in central Paris, including American rapper Snoop Dogg's, were on Palmer to see if he could retain the title he won when skateboarding made its Olympic debut at the Tokyo Games three years ago.
The US-born 21-year-old did not disappoint, leading from start to finish after laying down a score of 93.11 with his first run.
It was good enough to finish ahead of American Tom Schaar on 92.23 and Brazil's Augusto Akio on 91.85 and Palmer had the gold wrapped up before his final run.
At Golf National, home favourite Celine Boutier delighted the French crowds as she cruised into a three-shot lead after the opening round of the women's golf event.
Boutier poured in eight birdies in a brilliant seven-under-par round of 65.
South Africa's Ashleigh Buhai sits in second place, while Korda battled back from a poor opening stretch of holes to finish on even par, seven strokes behind Boutier.
The highlight of the evening's action on the track is expected to be the men's 400 metres, which features Britain's Matt Hudson-Smith, three fast Americans and Zambia's Muzala Samukonga, an unpredictable runner who looked good in the heats.
Hudson-Smith has arrived in Paris with the fastest time in the world this year to his name and is bidding to become the first British man to win an Olympic title in the one-lap event since Eric Liddell achieved the feat at the Paris Games a century ago.
In other action, Soufiane El Bakkali will attempt to win consecutive 3,000m steeplechase golds.
Spaniards Alvaro Martin and Maria Perez clinched gold in the inaugural marathon race walk mixed relay.
Poland's Aleksandra Miroslaw proved she is the undisputed queen of speed climbing taking gold by a fingertip ahead of China's Deng Lijuan after breaking her own world record with 6:06sec in qualifying.
"I never thought about the time. I only had one thing in my mind: just run. I didn't even look at the other side, I didn't even know it was close," Miroslaw said.
The first gold of the weightlifting programme went to Li Fabin, who retained his Olympic 61-kilogramme title.
The weightlifting is sure to aid China's battle at the top of the medals table with the United States.
In the boxing ring later Wednesday, Taiwan's Lin Yu-ting is aiming to follow in the footsteps of Imane Khelif of Algeria, by reaching a gold-medal bout.
The two are at the centre of a gender eligibility controversy that has overshadowed the boxing competition at these Games.
Algerian Khelif, who beat Janjaem Suwannapheng of Thailand in the semi-finals of the 66kg division on Tuesday, is guaranteed at least a silver medal.
The International Boxing Association disqualified Khelif and Lin from last year's world championships after failing gender eligibility tests.
The IOC cleared the two experienced female boxers to compete and Lin faces Turkey's Esra Yildiz Kahraman in the semi-finals of the women's 57kg event in the first fight of the evening at Roland Garros.
In track cycling, Australia won the men's team pursuit, beating Britain in the final by more than a second -- a relatively large margin by Olympic standards.
Meanwhile, India's wrestling federation are appealing the disqualification of star athlete Vinesh Phogat at the Paris Olympics after she failed to make the weight for the women's 50kg final.
Australian Olympic field hockey player Tom Craig has been arrested on suspicion of buying cocaine from a drug dealer in central Paris, police said.
Craig, 28, last played for Australia on Sunday in his team's quarter-final defeat to the Netherlands.
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