LONDON (CNN) -

A German tries again for a piece of gold medal history, and the sprint queens will find glory just around the corner.

Here are five things to watch at the Olympics on Wednesday:

1) Women's 200 meters: Jamaica vs. the United States

Veronica Campbell-Brown of Jamaica has won the past two Olympic 200 meters for women. But she was beaten at her national trials by Shelly-Ann Fraser-Pryce, who won the 100 meters on Saturday. They'll be keeping an eye on Allyson Felix of the United States, who ran the fastest time in the past 14 years in winning the U.S. trials. U.S. sprinters Carmelita Jeter and 400-meter winner Sanya Richards-Ross also have medal hopes.

Final is at 9 p.m. London time (4 p.m. ET)

2) Boxing: U.S. shutout avoided thanks to the women

While the U.S. men achieved an embarrassing first at the London Olympics by failing to win any medal, the American women are guaranteed two. Flyweight Marlen Esparza, who CNN profiled in the documentary "Latino in America: In Her Corner" and 17-year-old Claressa Shields, a middleweight, are in the semifinals of their divisions. A loss means a bronze, there are no third-place matches, and a win means a chance to be the winner of the gold medals in the inaugural events.

Matches begin at 1:30 p.m. London time (8:30 a.m. ET).

3) Men's decathlon: It's a new experience for the top contenders

Unlike most track and field events, the defending champion is not entered in the decathlon. Bryan Clay stumbled in the hurdles at the U.S. trials and failed to make the squad. But Ashton Eaton set a world record at the trials, and Trey Hardee was world champion in 2009 and 2011. They are both competing in the Olympics for the first time, as are Pascal Behrenbruch of Germany, Kevin Mayer of France, Hans Van Alphen of Belgium and Eelco Sintnicolaas of the Netherlands, meaning the podium will likely have three new visitors.

The first of the five events on Day 1, the 100 meters, is at 10:10 a.m. London time (5:10 a.m. ET)

4) Men's basketball: Win or go home

The knockout phase of the men's hoops tournament begins with Russia facing off against Lithuania. Team USA should have an easy time with Australia, which finished fourth in its group. It is a repeat of the situation at the 2008 Olympics when the United States trounced the Aussies 116-85. In other games France plays Spain and Argentina meets Brazil.

Games begin at 2 p.m. London time (9 a.m. ET) Team USA plays at 10:15 p.m. (5:15 p.m. ET)

5: Kayak: German seeks a gold for the fourth straight Games

Katrin Wagner-Augustin of Germany gets a second shot at becoming the second woman in Olympic history to win a gold medal at four consecutive Games. Lisa Leslie, who won gold with the U.S. basketball teams in 1996-2008, is the only other woman to do so. Wagner-Augustin failed again to win an individual gold when she finished fourth in her semifinal in the K1 500 meters on Tuesday but she hopes to add to her four golds in doubles (K2) and Fours (K4) with a win Wednesday.

Race starts at 10:44 a.m. London time (5:44 ET)