Paris Olympics roundup: Titmus and Dupont shine while tennis takes centre stage
Hosts France ran out 28-7 winners over reigning two-time Olympic rugby sevens champions Fiji in a pulsating final at a frenzied Stade de France.
Dupont, seen by many as the world's best 15-a-side player, came off the bench to mastermind a second-half performance in which he scored twice and created another try to inflict Fiji's first-ever loss at the Olympics.
"A huge reward for us, for rugby, for all the country," said Dupont.
"We really felt that we were representing not only rugby but the whole of French sport. We are really proud to start the Olympics like that."
Dominant Titmus
At La Defense Arena, a dominant Titmus held off great rivals Summer McIntosh and Katie Ledecky to successfully defend her 400m freestyle title in the pool, leading from start to finish.
The world record-holder was in full control to touch in 3mins 57.49secs ahead of Canada's McIntosh (3:58.37) and decorated American Ledecky (4:00.86), who faded badly in the final 50m.
"Oh my legs are a bit tired, but I'm just relieved more than anything," said Titmus, who will also swim the 200m and 800m in Paris.
"I probably felt the expectation and pressure for this race more than anything in my life to be honest, and I'm pretty good at handling the pressure, but I've definitely felt it."
Germany's Lukas Maertens surged to the men's 400m freestyle gold in 3:41.78, narrowly missing the world record.
The United States won the men's 4x100m freestyle relay gold and Australia triumphed in the women's race.
Rain disruption
China, who last topped the overall medals table in 2008 at Beijing, made a flying start to their latest bid for supremacy, bagging early golds in shooting and synchronised diving.
Teenage pair Sheng Lihao and Huang Yuting won the first gold of the Games in the mixed team 10-metre air rifle event, before all-conquering divers Chang Yani and Chen Yiwen somersaulted to victory in the women's three-metre springboard final.
Australia celebrated their first gold with cyclist Grace Brown speeding to victory in the women's individual time trial over 34.2 kilometres.
Belgium's Remco Evenepoel backed up his win at the world championships by defying rain and a strong field to win the men's event.
The wet weather which marred Friday's opening ceremony refused to go away for much of the day, before clearing in the evening, and the forecast is much better for the rest of the week.
The men's street skateboarding competition, due to take place at the Place de la Concorde in the historic heart of Paris, was postponed until Monday due to the wet conditions.
Tennis stars on show
The downpours also disrupted play at Roland Garros, but Novak Djokovic and French Open champions Carlos Alcaraz and Iga Swiatek all won.
Rafael Nadal admitted however that he does not know if he will play singles after picking up a thigh injury in training.
"I will talk to my people and make the smartest decision that I can to have the best chance of bringing a medal home, so let's see," he said after winning his first doubles match alongside Carlos Alcaraz.
Away from the sporting action, Canada's women's football team were deducted six points by FIFA and their coach Beverly Priestman suspended for a year after a drone spying scandal.
A drone was used over a New Zealand training session ahead of Canada's first match, which they won 2-1.
The punishment leaves the defending champions on minus three points in Group A, putting their future in the tournament in serious doubt.
France 'proud'
Friday's unprecedented opening ceremony - on the River Seine instead of at a stadium - has received mixed reviews.
Around 7,000 athletes paraded along the Seine in an armada of boats before a show-stopping finale that climaxed with a glittering light show at the Eiffel Tower and a performance from singer Celine Dion.
The International Olympic Committee was forced to apologise after South Korea's athletes were incorrectly introduced as North Korean.
France's President Emmanuel Macron said the bold showpiece had made the host country "extremely proud" but warned that security challenges remained.