It was another good day for Japan, China, and the United States on the twelfth day of the Rio Olympics as each nation asserted dominance in their favored sports.
Japan swept the gold medals on the first day of the Olympic women's wrestling tournament on August 17. Kaori Icho became the first wrestler in Olympic history to win four gold medals, beating Russia's Valeriia Koblova Zholobova 3-2 in the 58-kilogram women's freestyle.
Icho also was the first woman to win an individual gold medal in four straight Olympics, having started her historic run at the inaugural women's tournament in Athens in 2004.
Japan's Sara Dosho beat fourth-ranked Natalia Vorobeva of Russia in the 69-kilogram division, and Eri Tosaka beat Azerbaijan's Mariya Stadnik 3-2 to win gold in the 48-kilogram division.
China continued to dominate the Olympic diving events, while it swept the table tennis tournament, taking home every gold medal for the third Olympics in a row.
The Chinese men's team beat Japan 3-1 on August 17, cementing the nation's status as the world leader in the sport.
Chinese women have won every singles gold medal since the sport entered the Olympics in 1988.
This latest success pushed China up to 19 golds overall at Rio 2016, the same number as Great Britain but behind the United States with 30 gold.
For the United States, which has racked up a stunning 93 medals in all so far during the games, it was a time for track stars to shine.
Brianna Rollins gave the United States its first track medal of the Rio Olympics when she won the 100-meters hurdles final on August 17, leading compatriots Nia Ali and Kristi Castlin across the line for an American podium sweep.
The American trio shrieked in delight and jumped up and down on the track in an embrace when they realized they had achieved the first such sweep ever in the Olympic event.
Rollins's triumph left the United States with five gold medals in track and field, ahead of Kenya and Jamaica, two other powers in the sport.
U.S. athlete Tianna Bartoletta, a two-time world champion, also earned a gold medal in the long jump final with a life-time best jump of 7.17 meters.
Defending Olympic champion Brittney Reese of the United States took silver, while Ivana Spanovic of Serbia won bronze with a Serbian national record of 7.08.
But in a shocker for the American track team, star runner Justin Gatlin -- who had been expected to challenge Olympic legend Usain Bolt in a 200-meter race on August 18 -- failed to qualify for the final after placing third in his semifinal heat on August 17.
Usain Bolt. meanwhile, advanced to the final with the fastest time of the year and is now only one win away from his eighth Olympic gold medal.
While Americans were scoring well inside the Olympic stadium, three U.S. swimmers who finished their competition and were heading home from Rio got a rude awakening when they were pulled off the plane by Brazilian police, who wanted to question them about inconsistencies in their accounts of a street robbery last week.
The police also wanted to question gold medallist Ryan Lochte, who had given a vivid account of the mugging to the press, but he had already returned to the United States.
For the Olympic organizers, the day also brought bad news. Europe's top Olympic official was arrested in a dawn raid of his Rio beachfront hotel in connection with an investigation into ticket scalping.
The Brazilian police said they had discovered evidence linking the 71-year-old Irishman Pat Hickey to an international scheme to illegally pass Olympic tickets to touts who were reselling them at well above their original price.
And the outlook for future Olympics darkened as an American medical study concluded that within 70 years, most cities in the northern Hemisphere will be too hot to host the summer Olympics due to rising temperatures associated with climate change.