Swimming the final race of his Olympic career, Michael Phelps gilded his resume just a bit more, helping the U.S. men's 4x100m medley relay team claim the gold medal at London's aquatic center. Phelps turned away a surprising challenge from the Japanese team, which had the lead when he went into the water to swim butterfly, the relay's third leg.

It was the 18th gold medal of Phelps' record-setting Olympic career. He leaves the London 2012 Games with 22 Olympic medals overall.

Swimming in London's Aquatic Center, the U.S. women's 4x100m medley relay team set a new world record in winning a gold medal, with Allison Schmitt swimming freestyle to anchor a relay that finished two seconds ahead of the competition, at 3:52.05.

All four members of the women's relay team had previously won gold in their events: Dana Vollmer (butterfly), Missy Franklin (backstroke), Rebecca Soni (breaststroke), and Schmitt.

The victory gave Franklin, 17, four gold medals and one bronze in the London 2012 Games.

It's been a big day for Serena Williams. First, she started the day by winning her first individual Olympic gold medal. Then she earned a chance for another gold in the women's doubles match, playing with her sister, Venus. The pair defeated the Russian team of Nadia Petrova and Maria Kirilenko, 7-5, 6-4.

The Americans will next face the Czech team of Hlavackova and Kradecka in the Olympic final, Sunday at 7 a.m. ET.

The U.S. team won the silver medal in the inaugural women's team pursuit event of the Summer Olympics, finishing behind Great Britain in the final.

The British team set a new world record of 3:14.051 as they claimed the gold medal. The Americans finished 5 seconds behind them. Canada won the bronze-medal matchup, beating Australia in London's velodrome.

The American team of Sarah Hammer, Dotsie Bausch, and Lauren Tamayo averaged a speed of 54.073 Km/h, or 33.5 mph, on the track.

The U.S. men's doubles team of Bob and Mike Bryan won their first Olympic gold medal Saturday, beating France's Jo-Wilfried Tsonga and Michael Llodra, 6-1, 7-6 (6-2), in a game that was far more entertaining than its score might suggest. Both teams played creative and focused tennis, sustaining fast-paced volleys and inventing shots that delighted the crowd at Centre Court.

American Serena Williams stormed her way to an Olympic gold medal Saturday, dominating the final against Maria Sharapova of Russia. It is the first individual gold medal for Williams, who has twice won in Olympic doubles.

Williams won the first set, 6-0, in only 30 minutes. She hit only a handful of unforced errors in each set, and feasted on Sharapova's second serve. She won the second set by 6-1, with the entire match taking only a bit more than an hour to complete.

Good morning. As we start Day 8 of the London Olympics, big news is already happening. We posted earlier about Oscar Pistorius's historic run in the men's 400 meters, for instance. If you'd like to catch up on yesterday's events, check out our Day in Photos gallery. Here's what's been happening today:

The American men's basketball team has faced criticism for Thursday night's 156-73 blowout victory over Nigeria at the London Olympics. At the arena, NPR editor Vickie Walton-James spoke to Nigerian fans, to learn what they thought about being on the wrong end of a record score:

The vaunted USA Dream Team scored more points Thursday than any other team in an Olympic basketball game. The previous record was set in 1988, when Brazil scored 138 points to Egypt's 85.