London, England – Relays and distance races highlight track and field action Friday at the London Olympics.
The U.S. will try for a third consecutive gold medal in the men's 1,600-meter relay after clocking one of the fastest times in qualifying, along with the Bahamas.
The event will also give South African Oscar Pistorius another chance to compete, as his team was given a berth into the final after it was impeded during Thursday's heats.
An accident, in which a Kenyan runner collided with one of Pistorius' teammate, prevented South Africa from finishing the race. After an appeal, South Africa advanced and it gave Pistorius another shot at a medal. The double amputee, who runs with the help of carbon fiber artificial legs, became the first man to compete in both the Summer and Paralympic Games when he ran the 400m earlier at these games. He qualified for the semifinals with a season-best time, but didn't move on to the final.
Women will contest the 400-meter relay, and the United States and Jamaica are poised for an anticipated showdown.
The Americans posted the fastest time of the two heats Thursday, while the Jamaicans were second in their heat -- though mostly because of a poor baton hand-up.
A failed hand-up prevented Jamaica from medaling in the event at the last Olympics, while the U.S. didn't even get to the final. The Ukraine and Trinidad and Tobago also posted fast qualifying times and should be in contention for medals.
Women will compete in two distance races -- the 1,500 and 5,000. Ethiopian Tirunesh Dibaba headlines the 5,000 field and will look to complete another gold medal double. She won both the 5k and 10k at the 2008 Beijing Games, and got halfway to repeating the feat when she took first in the 10k a week ago.
The two other medalists from the 10k are in the 5k field -- Kenyans Sally Kipyego and Vivian Cheruiyot.
Americans Shannon Rowbury and Morgan Uceny will try for medals in the 1,500. Ethiopian Abeba Aregawi and Turkey's Gamze Bulut posted the top times in the semifinals.
Medals will be handed out in men's pole vault and women's hammer throw.
France's Renaud Lavillenie enters the pole vault as a favorite, having won the world indoor and European championships this year. Australian Steve Hooker returns as defending gold medalist.
In the hammer throw, German Betty Heidler is the world record holder but hasn't medaled at the Olympics. Belarus' Aksana Miankova is the defending champion.
Additionally, heats will be held for the women's 1,600m and men's 400m relays.
For the second consecutive Olympics, the United States and Argentina meet in a men's basketball semifinal. The Americans won in a rout four years ago in Beijing on the way to taking the gold medal, and have been mostly dominant during this tournament.
The U.S. is coming off a 119-86 defeat of Australia, while Argentina got past Brazil by five points.
In the other semifinal, Spain plays Russia with the aim of getting back to the final.
With the first Olympic medals in women's boxing decided, the men return to the ring Friday with semifinals in all 10 weight classes. The U.S. doesn't have a boxer left in any draw, but host Great Britain has four boxers still alive -- including welterweight Freddie Evans and middleweight Anthony Ogogo.
Japan and South Korea play for bronze in the men's soccer tournament, and it represents an opportunity for both teams to pick up a rare medal in the event. Japan won its only men's soccer medal in 1968, with a bronze, while South Korea has never finished on the podium.
After surviving the first penalty shootout game in Olympic field hockey history, the Netherlands' women's team will try to win a second gold medal in a row when it takes on Argentina.
The Dutch reached the final for the third consecutive Olympics. Argentina won bronze in 2008, but defeated the Netherlands at the 2010 world cup.
New Zealand, which lost to the Netherlands in the semifinals, plays Great Britain for bronze.
The last event of the diving program in London starts Friday with more Chinese divers among the favorites, although Australian Matthew Mitcham is the reigning Olympic champion in the men's platform.
Mitcham's upset of favorite Zhou Luxin in 2008 made him the only non-Chinese diver to win gold at the Beijing Olympics. Other contenders this year are Lin Yue, who won gold in the men's synchronized platform four years ago, and Chinese teammate Qui Bo, the 2011 world champion.
Great Britain's Tom Daley will also compete in the event, which begins with preliminary dives Friday and ends with two rounds on Saturday. After Daley and partner Peter Waterfield finished fourth in the synchro event here, British police arrested a 17-year-old for tweeting Daley that he let his deceased father down. Daley's father died of brain cancer last year.
The platform field also includes Americans Nicholas McCrory and David Boudia and Canadians Riley McCormick and Eric Sehn.
In canoe sprint action, there are heats and semifinals in four events -- men's canoe single, men's kayak single and double, and women's kayak single. All the races are 200 meters, a new Olympic distance.
The men's and women's BMX events will be decided Friday, when semifinals and finals take place. The United States has Alise Post and Brooke Crain competing in the women's competition, while Connor Fields and David Herman line up in the men's.
France will look to move another step closer toward defending its men's handball gold medal, as it plays Croatia in the semifinals. In the other semi, Hungary -- fresh off its upset of 2008 silver medalist Iceland -- takes on Sweden.
Light winds prevented sailing action Thursday, and could again Friday. But as it's scheduled, three classes are set to compete. The men's and women's 470 will hold medal races, while semifinals in the women's Elliott 6m match racing event are on tap.
The men's 10-kilometer swimming marathon will take place, and Greece's Spyridon Gianniotis and German Thomas Lurz -- the bronze medalist in Beijing -- enter as the favorites. Alex Meyer is competing for the U.S.
Russia is in good position to record its fourth straight gold medal sweep of the Olympic synchronized swimming events. Heading into Friday's free routine, it leads China by 1.1 points. Scores from both routines will be combined to determine the medal winners. Russia has won every gold in the team and duets competition since 2000.
Medals will be awarded in the women's 67kg and men's 80kg taekwondo classes, as well as the men's 55kg and 74kg freestyle wrestling competitions.
Italy continues its pursuit of its first men's volleyball gold medal in a semifinal against Brazil. The Italians knocked out the U.S., the defending Olympic champion, in the quarterfinals and have another tough opponent. Brazil took gold eight years ago in Athens, then earned silver in 2008. The other semifinal pits Bulgaria against Russia, the '08 bronze medalist.
Semifinals in men's water polo take place, with Croatia playing Montenegro and Italy playing Serbia. Hungary, the three-time defending Olympic champion, was knocked out by Italy in the quarterfinals.
Rhythmic gymnastics continues with the second day of competition. Russia closed out the first day in the top position for both individual and group all-around events, with Daria Dmitrieva and Evgeniya Kanaeva leading the charge. The top 10 individual athletes after Friday, as well as the eight highest-scoring teams, advance to the final, to be held this weekend.