This one will surely be seen as a victory for clean athletes over the dopers.

No doubt, that was Lilly King's take.

The feisty American stared down Yulia Efimova, a swimmer at the center of Russia's doping scandal, and then beat her in the pool Monday night.

King could hardly contain her satisfaction at capturing gold in the 100-meter breaststroke - especially given who was in the next lane.

"It just proves you can compete clean and still come out on top with all the hard work you put in behind the scenes, behind the meet, at practice and weight sessions," the 19-year-old Indiana University student said giddily. "There is a way to become the best and do it the right way."

Efimova arrived in Rio as one of the symbols of the massive Russian doping operation, an athlete who had already served a 16-month suspension and tested positive again this year for the now-banned substance meldonium.

Efimova was initially banned from the Olympics, but that decision was overturned on appeal. King took umbrage at Efimova's No. 1 finger wag during the semifinals, and the bad blood carried over to the final.

After glaring at Efimova in the ready room and giving her a look of disdain on deck, King led all the way to take the gold in 1 minute, 4.93 seconds. Efimova settled for the silver, more than a half-second behind. The bronze went to another American, Katie Meili.

Efimova was booed by many in the crowd when introduced before the race, though a smattering of Russian fans cheered her on.

"I really don't know how I even reached the final," Efimova said, her face red from crying. "It would have really been the end of a fairytale, a horrible dream, if I'd won gold. But that was all I could do right now."

Hungary's Katinka Hosszu became the first two-time gold medalist at the Olympic Aquatics Stadium, adding the women's 100 backstroke title to her world-record victory in the 400 individual medley.

Hosszu, known as the Iron Lady for her grueling schedule, propped herself on the lane rope and made a heart sign in the direction of her coach and husband, Shane Tusup.

The silver went to American Kathleen Baker.

"I knew that I could win," Hosszu said. "But I was so tired that I told the Hungarians before the race that I could get anything from first place to eighth place."

In another result sure to stir the doping debate, China's Sun Yang captured gold in the men's 200 free. Two years ago, he served a three-month suspension for taking a banned stimulant.

Yang rallied from his customarily slow start to pass South Africa's Chas le Clos, who went out fast and tried to hang on.

It nearly worked.

Yang surged to the front on the final lap, but Le Clos still managed to grab the silver. Conor Dwyer took the bronze, adding to the U.S. medal haul.

The third day of Olympic competition featured a couple of notable firsts: Rafaela Silva captured host Brazil's initial gold medal of the Rio Games and fencer Ibtihaj Muhammad became the only American ever to compete in the Olympics wearing a hijab.

The U.S. men's basketball team surged after a slow start, beating Venezuela 113-69, and Serena Williams struggled before beating France's Alize Cornet 7-6 (5), 6-2 in her bid for a second consecutive singles gold medal.

Silva, who grew up on one of Rio hillside shanty towns, won judo's 57-kilogram division, then, overwhelmed with emotion, performed the Brazilian version of the Green Bay Packers' "Lambeau Leap" to celebrate with her compatriots Monday.

It was, at the least, a momentary reprieve for the host country bracing for what once seemed unthinkable: an early exit by its men's soccer team from the Olympic tournament. Brazil finds itself needing a victory against Denmark to advance and avoid another huge embarrassment two years after a demoralizing 7-1 loss to Germany in the semifinals of the World Cup.

Brazilian fans aren't just booing their men's soccer team. After months of dire predictions from abroad about the mosquito-borne Zika virus, some locals are doing some stinging of their own: They're jeering U.S. athletes and taunting them over the fears that kept some competitors away from South America's first Olympics.

In the women's sabre tournament, Muhammad, sporting a plain black Muslim head scarf under a red, white and blue mask, was a winner in her opening bout before bowing out. A New Jersey native who started fencing in part because the uniform allowed her to adhere to the tenets of her faith, Muhammad also competes in the team event later this week.

Australia won the first gold medal for rugby sevens at the Olympics, beating archrival New Zealand 24-17 in the women's final Monday night.

A day after adding a record 19th gold medal to his collection, Michael Phelps is swimming the 200 meter butterfly semifinal Monday night and fellow American Katie Ledecky is swimming the women's 200 meter freestyle.

Other highlights from Day 3 of the Rio Games:

King took exception to Efimova, who has served a ban for doping and had her ban for the Rio Olympics overturned, raising her finger in the No. 1 sign after winning her heat in the semifinals. King beat Efimova in the final and crowed afterward about a clean victory. "There is a way to become the best and do it the right way," she said.

The first Olympic golf shot in 112 years will be hit by the lone Brazilian in the men's field. The International Golf Federation tapped into what few Olympic roots it has by selecting Adilson da Silva to be the first to tee off Thursday. Also in the opening threesome: Graham DeLaet of Canada, a country IGF President Peter Dawson called the defending champ — George Lyon of Canada won the gold medal at the St. Louis Games in 1904.

It has come to this for the Brazilian men's soccer team: The fans are so disappointed with the team that they heckled Neymar and chanted the name of the women team's star during a lackluster, scoreless tie against Iraq over the weekend. Brazil is now facing elimination — a prospect that once seemed unthinkable in the soccer-obsessed Olympic host country.

NBC announcer Al Trautwig says he regrets tweeting that the adoptive mother and father of U.S. gymnastics star Simone Biles were not her parents. Trautwig angered adoption advocates by refusing to refer to Ron and Nellie Biles as the 19-year-old's parents. Ron Biles, her maternal grandfather, and his wife Nellie adopted Simone 16 years ago. Trautwig said, "to set the record straight, Ron and Nellie are Simone's parents."

Sailing, not the dirty water, was finally the focus on troubled Guanabara Bay during a spectacular start to the Olympic regatta on Monday. Windsurfers sped across the waves toward Flamengo Beach in a fresh breeze, against the imposing backdrop of Sugarloaf Mountain. Robert Scheidt won the second race in the Laser class. He's trying to become the first Olympic sailor and first Brazilian to win six Olympic medals.