Updated

American women will try to end a Jamaican gold streak when the track and field competition continues Wednesday at the London Olympics.

Jamaican women won both the 100- and 200-meter races four years ago in Beijing and Shelly-Ann Fraser-Pryce moved the country one gold away from repeating that double here.

Fraser-Pryce claimed her second straight gold in the 100 meters on Saturday, beating silver medalist Carmelita Jeter of the U.S. by .03 seconds. Both women have qualified for the 200 semifinals and have excellent shots at medals, as did Jamaica's Veronica Campbell-Brown of Jamaica. Brown will try to become the first woman to win golds in the same track and field event at three straight Olympics.

There were few surprises in Tuesday's qualifications for the 200 semis, as Sanya Richards-Ross, the American who won gold in the 400 earlier in London, posted the fastest qualifying time with a run of 22.30 seconds. Allyson Felix of the U.S. -- silver medalist in Beijing -- was next with a time of 22.31 seconds.

Gold will also be on the line for the women in the long jump and the 400-meter hurdles and the men will battle in the 110-meter hurdles.

The decathlon will also start Wednesday with athletes competing in the first five of 10 disciplines. Ashton Eaton of the U.S. is the world record holder and is the favorite to win gold. Medals will be awarded after the last five events are run on Thursday.

After a mostly dominant run through group play, the United States men's basketball team takes on Australia in a quarterfinal matchup. The U.S. was the only team to go unbeaten in the preliminary round, averaging 117.8 points per game. The Americans have won four of the last five gold medals, with the only failure coming in 2004, when Argentina won. The U.S. could have a semifinal matchup with Argentina, which faces Brazil in the quarters.

On the other side of the bracket, France plays Spain and Lithuania takes on Russia.

It will be an all-American women's beach volleyball final Wednesday at Horse Guards Parade when two-time reigning Olympic champions Misty May-Treanor and Kerri Walsh Jennings face teammates Jennifer Kessy and April Ross with gold and silver medals on the line.

May-Treanor and Walsh Jennings will try to become the first beach volleyball pair, male or female, to win three Olympic gold medals. They beat 2008 bronze medalists Xue Chen and Zhang Xi of China in two sets Tuesday, while Kessy and Ross knocked off top Brazilians Juliana and Larissa in three.

China and Brazil will meet in the bronze medal match, also Wednesday at the temporary venue not far from the British Prime Minister's front door.

Boxing action is highlighted by semifinal bouts in all three women's draws. Two Americans are fighting -- flyweight Marlen Esparza against China's Ren Cancan, and middleweight Claressa Shields vs. Kazakhstan's Marina Volnova. There are also quarterfinal fights in the men's flyweight, light welterweight and light heavyweight draws.

Canoeing features finals in the men's single and double kayak, as well as single canoe. All of those events are 1,000 meters. The finals of the 500- meter women's kayak fours also takes place.

In sailing, there is a medal race in the men's 49er class, while the quarterfinal matchups in the women's Elliott 6m match racing competition hit their second day. The women's 470 class holds its final two opening series races.

China will attempt a gold medal sweep of table tennis events for a second consecutive Olympics, as the men's team faces South Korea in the final. Germany and Hong Kong square off for bronze.

Meanwhile, Great Britain will hope to advance to the gold medal match of the men's field hockey tournament, as it plays Argentina in a semifinal. The British have not won gold in men's field hockey since 1988. The Netherlands and New Zealand contest the other semifinal.

Also, the United States will look to move one step closer to another gold medal in men's volleyball, as it plays Italy in the quarterfinals. Additionally, the U.S. plays Croatia in the quarterfinals of men's water polo, and event in which it earned silver four years ago in Beijing.

Meanwhile, medals will be awarded in the women's 49kg and men's 58kg taekwondo categories, as well as the women's 48kg and 63kg freestyle weight classes. Quarterfinal matches will take place in men's handball, and BMX has seeding runs for men and women.

Preliminary dives for the women's 10-meter platform will be held Wednesday with China's Chen Ruolin a strong favorite. Chen already has a gold medal here after winning the synchronized platform event with Wang Hao, but China can no longer sweep the diving competition at these games. That's because Russia's Ilya Zakharov used a big final dive Tuesday night to beat Qin Kai and He Chong to win the men's 3-meter springboard.

Several countries are in line to add to their medal haul in equestrian on Wednesday after the final rounds of individual jumping.

Great Britain's Nick Skelton and Netherlands teammates Maikel van der Vleuten and Marc Houtzager share the lead with clean scores after three qualifiers while reigning Olympic champion Eric Lamaze is tied for 22nd place with 9 penalties. American Rich Fellers is knotted in 11th with 8.