PARIS — Simone Biles reached the top of the podium yet again, cementing her legacy as the greatest American gymnast and one of the best athletes in the history of the Olympics.

Biles helped the United States win the women's team event Tuesday to secure her fifth Olympic gold medal and put the U.S. back on top of the sport after a second-place finish three years ago in Tokyo.

Biles became the most decorated American gymnast in front of a crowd that included Nicole Kidman, Natalie Portman, Serena Williams, Spike Lee, Michael Phelps and Nadia Comaneci at a raucous Bercy Arena.

It was the eighth Olympic medal for the 27-year-old Biles, who was previously tied with Shannon Miller at seven.

Italy won the silver medal, and Brazil got the bronze.

There were no such triumphs in swimming for the Americans, who couldn't manage more than silver and bronze medals. In tennis, it was Coco Gauff left fuming over an officiating decision in a loss to Donna Vekic of Croatia.

There were no winners or losers in men's triathlon, which was as postponed because of concerns about the water quality in the Seine River amid a heat wave that made life difficult on some athletes and fans in Paris.

Australian Kaylee McKeown knocked off world record holder Regan Smith of the United States in the 100 backstroke to defend her title from the Tokyo Games.

Smith couldn’t hold off the hard-charging Aussie, who touched the wall in 57.33 seconds to win by a relatively comfortable margin over Smith’s 57.66. The U.S. also grabbed the bronze with Katharine Berkoff.

In the men’s 800 freestyle, Daniel Wiffen won Ireland’s first gold medal in swimming since scandal-plagued Michelle Smith won three events in 1996. Defending champion Bobby Finke of the U.S. got the silver.

The night’s other gold medal went to Britain, which defended its title in the men’s 4x200 freestyle relay, with the U.S. earning yet another silver.

The scene felt all too familiar to Gauff. An officiating decision she was sure was wrong. A chair umpire who wouldn’t listen. Tears streaming down her cheeks. And, most disappointing of all, a loss, this time at the Paris Games.

Even the site was the same: Court Philippe Chatrier was where the reigning U.S. Open champion was eliminated in the third round at the Summer Games by Donna Vekic of Croatia 7-6 (7), 6-2.

That’s also the main stadium used annually for the French Open, where Gauff found herself in a nearly identical dispute over a call while being defeated by eventual champion Iga Swiatek in the semifinals last month.

“There’s been multiple times this year where that’s happened to me — where I felt like I always have to be an advocate for myself on the court,” Gauff said afterward, renewing a call for video review to be used in tennis, as it is in many other professional sports.

Gauff was the female flag bearer for the United States during the opening ceremony Friday.

Also in tennis, Rafael Nadal and Carlos Alcaraz advanced into the doubles quarterfinals with a 6-4, 6-7 (2), 10-2 match tiebreaker victory over Tallon Griekspoor and Wesley Koolhof of the Netherlands.

No. 1-ranked Iga Swiatek defeated No. 52 Wang Xiyu of China 6-2, 6-4.

The men’s triathlon was rescheduled for Wednesday, when the women’s competition is also slated to be held. But both will happen only if water tests in the Seine River show acceptable levels of E. coli and other bacteria. Friday is also planned as a backup date.

There is rain forecast Tuesday night through Thursday, which could complicate rescheduling because rain generally causes an increase in bacteria levels in the Seine, the long-polluted waterway that has gone through an expensive cleanup effort.

“It’s disappointing that there’s this negative aspect now with the delay,” American triathlete Seth Rider said. “But I hope we can have a triathlon and I can accomplish this dream that I’ve had since I was a little kid.”

After enduring the rain in the opening ceremony, athletes now are having to deal with the heat.

Most of France is under heat warnings, with temperatures in Paris hitting 97 Fahrenheit, the national weather agency said. Air conditioning is far less common in French homes, shops and restaurants than in places like the United States.

The heat was even worse in the south, including the region around the Mediterranean cities of Marseille and Nice that are hosting Olympic competitions like soccer and sailing. It was as hot as 105 F in parts of southern France.

Before winning the gold Tuesday, Biles posted a video on Instagram while struggling with the lack of air conditioning.

“Don’t come for me about my hair,” Biles wrote on Instagram before the gymnastics team final. “IT WAS DONE but bus has NO AC and it’s like 9,000 degrees. Oh & a 45 minutes ride.”