Michael Phelps, Missy Franklin and Katie Ledecky all won gold for the United States during three consecutive events in the pool, and each performance was nothing less than stunning.
They were among the highlights on a day that brought much more success for the home team and also saw the American contingent surprisingly take the lead in the number of gold medals won around the busy Olympic venues.
The women's soccer competition reached its semifinal stage with the chances growing of a World Cup rematch, and the finals were set at Wimbledon, where four of the game's superstars will battle for gold medals.
No matter the other results, however, the chief focus Friday was on Phelps.
He swam the final individual race of his career, which has seen him become the most decorated athlete in the history of the Olympics.
His finale did not look to be all that memorable, however, when he reached the halfway point of the 100-meter butterfly in seventh place. During his next trip down the length of the pool, he delivered one of the most impressive performances of his career.
Phelps churned past his rivals, pulled ahead with about 20 meters to go and won an Olympic race for the 17th time. It was his 21st career Olympic medal overall. When he swam the 200-meter individual medley Thursday he became the first swimmer in Olympic history to win the same event three times. On Friday he did it again.
The achievements turned in just before and after Phelps swam were equally impressive.
Missy Franklin shattered the world record in the 200-meter backstroke by three-quarters of a second to win her third gold medal of the Games, the same number won by Phelps. Franklin is only 17.
And after Phelps' race, Ledecky made her Olympic debut. She set a blistering pace in the 800-meter freestyle, one that seemed certain to leave her spent over the final stages of the grueling race. As it turned out, the other swimmers were the ones who slowed down while Ledecky kept going and she delivered the second-fasted time in the history of the event.
Ledecky is 15 and has already made her mark on the Olympics.
British athletes made their mark again as well Friday with a win in rowing and two more in cycling.
That brought Britain's gold medal total to eight, leaving them behind only South Korea, China and the United States. The American haul in the pool raised the United States' gold total to 21 -- one more than the Chinese.
The American women's soccer team advanced to the semifinals with a 2-0 victory over New Zealand that featured the fourth goal in as many games from Abby Wambach.
Japan also reached the semifinals, and if the Japanese defeat France and the Americans down Canada, there will be a rematch of last year's World Cup final. Japan won that one.
A rematch was assured for the men's tennis final, which will bring together Swiss legend Roger Federer and British hero Andy Murray. They faced each other last month on Centre Court at Wimbledon, where Sunday's gold medal match will take place. Federer was the winner on that occasion.
In the women's final, American Serena Williams will take on Russian Maria Sharapova after they recorded semifinal wins Friday. Both have won the career grand slam, so one of them will earn what is referred to in the Olympics as the career Golden Slam.
The day ended with the first two finals in track and field, where both Polish shot putter Tomasz Majewski and Ethopian 10,000-meter runner Tirunesh Dibaba won their events for the second Olympics in a row.
No Russian finished second in either event, although if there had been any in the finals they might have.
Throughout the typically long day of Olympic endeavors, not a single Russian won a gold medal. But in trampoline, judo, twice in swimming and twice in weightlifting they finished as the runner-up. That brought about three times more silver medals than were won by any other country.