PARIS -- Celebrating its reputation as a cradle of revolution, Paris kicked off its first Summer Olympics in a century Friday with a rain-soaked, rule-breaking opening ceremony studded with stars and fantasy along the Seine River.

On-and-off showers did not seem to hamper the enthusiasm of the Olympians, with some holding umbrellas as they rode on boats down the river in a showcase of the city's resilience as authorities dealt with suspected acts of sabotage targeting France's high-speed rail network.

Widespread travel disruptions triggered by what French officials called coordinated arson attacks on high-speed rail lines as well as the weather had dampened the mood ahead of the ceremony.

Crowds crammed along the Seine's banks and bridges and watching from balconies "oohed" and "aahed" as Olympic teams paraded in boats down the waterway. Undeterred from the festivities, many of the hundreds of thousands of spectators huddled under umbrellas and jackets as the rain intensified, though some dashed from their seats to seek shelter.

As global audiences tuned in, Paris put its best foot forward -- quite literally, with a spectacular launch that lifted spirits and joyous French cancan dancers featured early on. A humorous short film featured soccer icon Zinedine Zidane. Plumes of French blue, white and red smoke followed. And Lady Gaga sang, in French, with dancers shaking pink plumed pompoms, adding a cabaret feel to what is expected to be a more than three-hour show.

French-Malian pop star Aya Nakamura, the most listened-to French-speaking artist in the world, sang her hit "Djadja" accompanied by the orchestra of the French Republican Guard. She emerged from a pyrotechnic display, wearing an all-gold outfit as she performed with a Republican guard band of the French army.

Merging the elements of opera and rock metal music on the global stage, band Gojira brought its progressive and technical death metal style, while singer Marina Viotti inserted her mezzo-soprano vocals.

The sprawling ceremony gave organizers bigger crowds to transport, organize and safeguard than would have been the case if they'd followed the example of previous Olympic host cities that opened with stadium shows.

Still, as the show got underway, optimism soared that Paris -- true to its motto that speaks of being unsinkable -- might just see its gambles pay off.

Paris organizers said 6,800 of the 10,500 athletes would attend before they embark on the next 16 days of competition.

The boats carrying the Olympic teams started the parade by breaking through curtains of water that cascaded down from Austerlitz Bridge, the start of the 6-kilometer (nearly 4-mile) parade route. The jetting waters were a wink at the splendid fountains of Versailles Palace, now the venue for Olympic equestrian competitions.

Per Olympic protocol, the first boat carried athletes from Greece, birthplace of the ancient Games. It was followed by the Olympic team of refugee athletes, and then the other nations in French alphabetical order.

Usually during Olympic opening ceremonies, the parade of athletes takes place during a pause in the razzmatazz. But Paris shattered that tradition by having the parade and pageantry at the same time, blending sports and artistic expression.

Paris had plenty of aces up its sleeve. The Eiffel Tower, its head still visible below the clouds, Notre Dame Cathedral -- restored from the ashes of its 2019 fire -- the Louvre Museum and other iconic monuments will star in the opening ceremony. Award-winning theater director Thomas Jolly, the show's creative mind, was using the signature Paris cityscape of zinc-gray rooftops as the playground for his imagination.

His task: Tell the story of France, its people, their history and essence in a way that leaves an indelible imprint on Olympic audiences. Refresh the image and self-confidence of the French capital that was repeatedly struck by deadly extremist attacks in 2015. Capture how Paris is also aiming to reboot the Olympics, with Summer Games it has worked to make more appealing and sustainable.

Zidane, who led France to World Cup ecstasy in 1998, was among the guesses for who might light the Olympic cauldron. Another suggestion is that organizers might bestow that honor on survivors of the 2015 attacks by Islamic State-group gunmen and suicide bombers who killed 130 people in and around Paris.

The identity of the final torchbearers has been the country's biggest secret. Chief Paris Games organizer Tony Estanguet said Friday morning that only he knows "the personality or athlete" and that he still hadn't told that person.

"I plan to tell the last carrier today," he said. "He or she doesn't know."

The ceremony's broad brushstrokes have been previously announced and are stunning in their ambition. French President Emmanuel Macron said they initially felt like "a crazy and not very serious idea."

During the athletes' waterborne adventure, Paris' splendors unfurled before them. They were passing historic landmarks that have been temporarily transformed into arenas for Olympic sports.

Concorde Plaza, where French revolutionaries guillotined King Louis XVI and other royals, now hosting skateboarding and other sports, and the Grand Palais of iron, stone and glass, the fencing and taekwondo venue.

The golden-domed resting place of Napoléon Bonaparte, the backdrop for Olympic archery, and the Eiffel Tower, which donated chunks of iron that have been inlaid in the gold, silver and bronze Olympic medals. They'll be won in the 32 sports' 329 medal events.

Up to 45,000 police and gendarmes, plus 10,000 soldiers, were safeguarding the ceremony and its VIP guests, with IOC president Thomas Bach and Macron presiding.

Paris' aim, said Estanguet, is "to show to the whole world and to all of the French that in this country, we're capable of exceptional things."

The Associated Press contributed to this report.