China bags early Olympic golds as swimming takes centre stage

China grabbed the first two gold medals at the rain-disrupted Paris Olympics on Saturday as Katie Ledecky and Ariarne Titmus prepared for a titanic duel in the pool.

Asian powerhouses China, who last topped the Olympic medal table in 2008, 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 Chinese gold 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 its 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.

A total of 13 golds were up for grabs in Paris on Saturday as wet weather continued to cause headaches for organisers following Friday's deluge at the opening ceremony.

The men's street skateboarding competition, due to take place at the Place de la Concorde in the historic heart of the city, was postponed until Monday due to the wet conditions.

The downpours also disrupted play in the opening rounds of tennis at Roland Garros, with dozens of matches cancelled or rescheduled.

Torrential rain had lashed participants and spectators in Friday's amphibious opening ceremony.

Around 7,000 athletes paraded along the River Seine in an armada of boats before a show-stopping finale which climaxed with a glittering light show at the Eiffel Tower and a performance from singer Celine Dion.

The ceremony received broadly favourable reviews, with France's centre-right Le Figaro daily describing it as "full of surprises but often disjointed".

The International Olympic Committee however was forced to apologise for a gaffe during the ceremony, with South Korea's athletes incorrectly introduced as North Korean.

France's President Emmanuel Macron on Saturday said the bold showpiece on the Seine had made the host country "extremely proud" but warned that security challenges remained.

"The next weeks will be difficult even if we have now passed a fundamental stage," he said.

- Swimming duel -

Elsewhere on the sporting front, swimming was preparing for a battle royale at La Defense Arena.

Traditionally one of the highlights of the opening week of the games, Saturday's first wave of swimming finals will feature a blockbuster women's 400m freestyle duel pitting American great Ledecky against Australia's defending champion Titmus.

Ledecky, stunned by Titmus in Tokyo three years ago, laid down a psychological marker after pipping the Australian in Saturday's heats.

Titmus however rejected suggestions that the heats had given her rival an edge for Saturday's final.

"It's a heats swim," said the Australian, who broke the 200m freestyle world record and swam the second-quickest 400m ever at the Australian trials last month.

"The only job for me was to get in the middle lanes (for the final) and I tried to conserve as much as I could."

Other gold medals on offer on the first night of action in the pool come in the men's 400m freestyle and the men's and women's 4x100m freestyle relays.

In rugby sevens host nation France stayed on course for a gold medal after advancing to a dream final against Fiji at the Stade de France later Saturday.

French rugby idol Antoine Dupont helped the hosts defeat South Africa 19-5 in the semi-finals while Fiji comfortably downed Australia 31-7.

Elsewhere on Saturday, there were wins for Spanish star Carlos Alcaraz, top seed Novak Djokovic and women's world number one Iga Swiatek as the Olympics tennis tournament got under way at a sodden Roland Garros.

Djokovic said his 6-0, 6-1 win against doubles specialist Matthew Ebden in just 53 minutes was "not a good image" for tennis.

In the men's football Argentina's men's team bounced back from defeat in their opening match, which was marred by crowd trouble, to beat Iraq 3-1.

The surfing competition is due to start 16,000 kilometres (9,950 miles) kilometres away on the French Pacific island of Tahiti.