A sensational day for the US track-and-field team saw them claim four golds to extend their lead in the medal table. There were also firsts in boxing and taekwondo, while Brazil finished their sailing regatta in style.
Even for such a historically strong track-and field-nation, the United States enjoyed a remarkable Day 13 of the Rio Games on Thursday
Kerron Clement started it all off with the first track gold of the day - in the men's 400 meter hurdles. The American stormed to victory in 47.73 seconds, holding off the challenge of Kenya's Boniface Tumuti, who won silver in 47.78.
There was more gold for the medal-table leaders when Ashton Eaton clinched his second successive men's decathlon gold later in the evening. Eaton matched the 8,893-point Olympic record, leaving Frenchman Kevin Mayer to take silver and Canada's Damian Warner with bronze.
Just minutes later, 400-meter hurdler Dalilah Muhammad joined the American party on a now-damp Rio track. Muhammad led from the front to power her way to gold in a time of 53.13 seconds. Denmark's Sara Slott Petersen won silver and another American, Ashley Spencer, took bronze.
Ryan Crouser was the next American winner, clinching shot-put gold with an Olympic record throw of 22.52 meters. Crouser's compatriot Joe Kovacs took silver and New Zealand's Tomas Walsh bronze.
A little earlier the US had been out on their own in another sense as the women's 4x100 meter team were forced to re-run their race alone on the track after Allyson Felix was bumped by a Brazilian rival in the earlier heats. In the end, despite the bizarre nature of the situation, they qualified easily in 41.77 seconds.
Brownlee brothers at the double
The triathlon saw a 1-2 not only for Great Britain but for the Brownlee family, with Alistair, 28 and Jonny, 26, winning gold and silver respectively in the testing heat of Rio.
The older Brownlee brother is the first triathlete to retain the Olympic title and his brother moves up a notch after he won bronze in London 2012. They are the first brothers to take the top two medals in the same Summer Olympics event since Italian showjumpers Raimondo and Piero D'Inzeo in 1960.
"It's just an amazing feeling really, Alistair said. "When he crossed the line I just said 'we've done it'. To see your little brother come over the line 10 seconds after you is phenomenal. It's so satisfying. We've worked so hard together, for each other."
Firsts in hockey and boxing
Argentina stormed to their first men's field hockey gold medal with a thrilling 4-2 win over Belgium. The Argentines went behind early before goals from Pedro Ibarra, Ignacio Ortiz and Gonzalo Peillat put them in command. After Belgium pulled one back, a breakaway goal from Agustin Mazzilli in the dying seconds confirmed the win. Earlier, Germany beat rivals the Netherlands 4-3 on penalties to claim bronze after a tense 1-1 draw.
In the ring, Cuban Julio Cesar La Cruz beat Kazakhstan's Adilbek Niyazymbetov to become his country's first light-heavyweight Olympic champion in the only gold medal match of the day.
Wrestler Risako Kawai gave Japan their fourth women's wrestling gold of the Games with a victory over Mariya Mamashuk of Belarus in the 63-kilogram class and Canada's Erica Wiebe clinched gold (75 kilograms) in the final bout of the day with victory over Guzel Manyurova of Kazakhstan.
In taekwondo, Ahmad Abughaush won Jordan's first- ever Olympic medal - a surprise gold in the 68-kilogram division - while Britain's Jade Jones won her second successive gold in the 57-kilogram category. Jones, who also won in London four years ago, beat Spain's Eva Calvo Gomez 16-7 in the gold medal match while Abughaush beat Russia's Alexey Denisenko 10-6.
Brazil ended their sailing regatta on a high when Martine Grael and Kahena Kunze won gold in the women's 49erFX class, which was making its Olympic debut. It was the host nation's only sailing gold of the Games. New Zealand's Peter Burling and Blair Tuke won the men's event, with Australia claiming bronze and Germany silver.
Away from sport, there were further developments in the mysterious case of the f four US swimmers and Kyrgyzstan's weightlifter Izzat Artykov was stripped of his bronze medal following a positive drug test.