Brazil won its first gold as the host nation of the 2016 Summer Games, rugby returned to the Olympics and Twitter continued to shower appreciation on the parents of gymnast Aly Raisman, who rivaled their daughter in a performance from the stands. In you missed any of Monday's excitement, here are highlights from the day's competition in Rio.
U.S. swimmer Lilly King won the gold in the 100-meter breaststroke, defeating Yulia Efimova, a Russian competitor who has been embroiled in a doping controversy.
King's victory came after the women clashed earlier over Efimova's 16-month suspension for doping and her more recent positive test for the now-banned substance meldonium.
King objected when Efimova wagged her finger, seemingly signaling she was number one, after winning a semifinal on Sunday. King wagged her own finger back when she bested Efimova's time in her own semifinal.
"You know, you're shaking your finger No. 1, and you've been caught for drug cheating, I'm just not a fan," King said on Sunday.
Asked if she thought she had made a statement with her win on Monday, King said, "I hope I did, that we can still compete clean, and do well at the Olympic Games, and that's how it should be."
After losing Monday, Efimova told The Associated Press: "I really don't know how I even reached the final ... it would have really been the end of a fairytale."
From Favela to Gold
Brazil's Rafaela Silva, who rose to the top of her sport from her childhood home in Rio's most dangerous favela, took the first gold medal for the host country on Monday.
Silva, 24, won in judo in the 57-kilogram division, beating Sumiya Dorjsuren of Mongolia. The country's first female world champion in judo, she lived in the City of God, notorious for deprivation and gangs, until her parents were able to move to a nearby neighborhood. She trained at a judo school in a large favela in southern Rio, established by Flávio Canto, a two-time Olympian who won a bronze medal at the Athens Games in 2004.
On Monday, she said support from her fans and family helped her defeat her opponent.
"The stadium was shaking, everybody was screaming and cheering me up every minute," she said.
She was disqualified in the London Games for an illegal hold, and afterward was called a "monkey" by a troll on the Internet.
Her father, Luiz Carlos, was too nervous to attend his daughter's preliminary fights, but was there for the final, next to his wife, Zenilda.
"She deserves this," her mother said. "She is a unique warrior. A warrior of gold."
A Rugby First
The last time men played rugby at the Olympics Games was 1924.
The last time women played? Never.
On Monday, the first Olympic gold medal for women went to Australia, the World Series champion, which outlasted a late New Zealand rally to win 24-15.
Australia had beaten Canada to reach the final match, while New Zealand had gone up against Britain. For the bronze, Canada beat Great Britain.
The game was rugby sevens, which for the uninitiated is a variant of rugby union. Teams of seven play 7-minute halves instead of the usual 15 playing 40 minutes a half.
In 1924, the United States won the gold in a surprise victory against France, playing the 15-side version. It was the second time the U.S. team had beaten France in a gold medal match.
The U.S. men compete against Argentina on Tuesday afternoon. Underdogs against such powerhouses as Fiji and New Zealand, they do have the fastest man in rugby, Carlin Isles, who once hoped to be on the track and field team instead.
U.S. Basketball Dominates Again
The U.S. women's basketball team defeated Spain 103-63, following a record-breaking feat the day before.
On Sunday, the U.S. women beat Senegal 121-56, the most points scored in the Olympics. The U.S. is going for its sixth straight Olympic gold medal.
Monday's victory was the 43rd consecutive for the U.S. in the Olympics.
On the men's side, the U.S. cruised past Venezuela 113-69.
The four smaller stars on China's five-starred red flag didn't tilt as they should have toward the largest star, leaving China irritated and Rio organizers embarrassed.
By Monday, Olympic officials had ordered new flags to replace the gaffe-marred version, one of which had been carried into the opening ceremony by China's flag-bearer, fencer Lei Sheng.
A quick look at a few earlier bloopers.
At the leading global soccer tournament in June, the Copa America, the national anthem of Chile was played instead of one for Uruguay, leaving the Uruguayan players standing silently.
And at the London Olympics in 2012, the South Korea flag was displayed instead of the one from North Korea. The North Korean women’s soccer team refused to take the field for about an hour.
Talk of Twitter
Aly Raisman’s parents anxiously squirmed in their seats as the U.S. women’s team captain qualified for the individual all-around final taking place on Thursday. Raisman bested teammate and defending Olympic all-around champion, Gabby Douglas, for one of two American spots in the final. The other spot went to Simone Biles.
But matching the excitement on the arena floor was the drama in the stands as Raisman’s parents, Rick and Lynn Faber Raisman, could barely contain their nerves. Lynn Raisman covered her eyes, leaned away from the floor and clutched her husband’s arm before jumping up to clap. It was a repeat performance from the London Games
Fans were still tweeting their approval on Monday, eager to award them their own Olympic medal.