Paris Olympics: What you need to know right now

Enfin! A yellow disc has appeared in the Paris sky. And with it, the biggest star of the Games, gymnast Simone Biles, dazzled in her opening routine.

The rain has moved on and the Olympic venues set among the French capital's most famous landmarks will finally bathe in the warmth and light Paris 2024 organisers had been dreaming of.

Here's what you need to know about the Olympics on Sunday.

Biles back with a bang

A radiant Simone Biles made her long-awaited Olympic return in Paris on Sunday, drawing boisterous cheering and clapping from an ecstatic, star-studded crowd in the French capital.

The most decorated gymnast in history is returning for her third Olympics after suffering from the "twisties" at the Tokyo Games, a term used by gymnasts to describe a temporary loss of spatial awareness when doing high-difficulty elements.

Biles began the competition on the balance beam and was awarded a competition-leading 14.733 points.

Opening ceremony controversy

Overview of the Trocadero venue, with the Eiffel Tower looming in the background while the Olympic flag is being raised, during the opening ceremony of the Paris 2024 Olympic Games. PHOTO: REUTERS

Paris 2024 organisers apologised on Sunday to Catholics and other Christian groups angered by a kitsch tableau in the Olympic Games opening ceremony that parodied Leonardo Da Vinci's famous 'The Last Supper' painting.

The segment, which recreated the biblical scene of Jesus Christ and his apostles sharing a last meal before the crucifixion, featured drag queens, a transgender model and a naked singer made up as the Greek god of wine Dionysus, and drew dismay from the Catholic Church.

Convicted rapist volleyball player booed

There were a few boos among the crowd as Netherlands beach volleyball player Steven van de Velde, a convicted rapist, made his Paris 2024 debut.

Van de Velde was sentenced to four years in prison in Britain in 2016 following the rape of a 12-year-old girl two years earlier when he was 19.

In-Seine?

France's 1.4 billion euro ($1.52 billion) gamble to hold the triathlon swimming in the River Seine hangs in the balance after organisers were forced to cancel a training session on Sunday due to excessive pollution levels.

"The tests carried out in the Seine yesterday revealed water quality levels that in the view of the international federation, World Triathlon, did not provide sufficient guarantees to allow the event to be held," said Paris 2024.

Efforts to make the once-murky Seine waters fit for swimming in time for the Games include a giant subterranean reservoir designed to prevent rainwater runoff from mixing with the capital's wastewater.

Allez les Bleus!

Smoke clouds in the tricolours of the France flag are seen at Pont d'Austerlitz during the opening ceremony. PHOTO: REUTERS

France crushed hot favourites Fiji 28-7 to win gold in the men's rugby sevens in front of a delirious home crowd.

Double-defending champions Fiji had won all 17 of their previous matches in the Olympics but had no answer to the high-impact appearance of French talisman Antoine Dupont in the second half as the hosts scored four tries.

Freestyle battle

Australia's Ariarne Titmus made a golden start at the Paris Games, beating Canadian teenager Summer McIntosh and American great Katie Ledecky to win the women's 400 metres freestyle.

The crowd was hollering from the start of a contest that had been compared to the epic men's 200 freestyle "Race of the Century" in 2004.

Australia's women swimmers added another gold in the 4x100 metres freestyle relay.

Surf's up

Teahupo'o served up some brutal barrels as the Olympic surfing got underway in Tahiti with the U.S. team setting the standard. Vahine Fierro, surfing in her first Olympic heat at her home break, was another standout.