Serena and Venus Williams began the ninth day of the 2012 London Olympics by taking home another gold for the U.S. They beat the Czech Republic to win the women's doubles tournament this morning.
The win comes just 24 hours after Serena took home the gold for the women's singles tournament on Saturday, becoming the second woman ever to complete the Golden Slam, made up of four grand slam titles and the Olympic gold.
The sisters have won the doubles tournament at the past two summer Olympics, in Sydney and Beijing.
Following the tennis match, attention will likely shift to the much-anticipated Olympic debut of women's boxing today.
Seattle's Queen Underwood will be the first American woman in history to complete in the Olympics as a boxer when she takes on Great Britain's Natasha Jones at 2:30 p.m. EDT.
Sunday's events will begin the second full week of Olympic competition, featuring individual gymnastics competitions, team sports like basketball and softball, and track events.
The United States and China head into the second week tied for the number of gold medals won so far; both countries have brought home 27 golds.
On Saturday, all eyes were on the beginning of the track competitions as top sprinters Tyson Gay, Usain Bolt, Carmelita Jeter, and Shelly-Ann Fraser-Price took the track. Bolt and Gay both won their heats for the 100 meter dash final, while Jeter scored the fastest runner-up time in Olympic history when she came in second to Jamaica's Fraser-Price in the women's 100 meter.
The host country, the United Kingdom, produced three gold medal winners at Olympic stadium, with Mo Farrah winning the 10,000 meter run, Greg Rutherford taking the top prize in the long jump with a distance of 8.21 meters, and track star Jessica Ennis taking top honors in the heptathlon.
The final for the men's 100 meter dash takes top billing at 4:50 p.m. today, when the fastest man in the world, Jamaica's Usain Bolt, tries to defend his title. Runners trying to out-sprint Bolt include the second fastest man in the world, Tyson Gay of the U.S. Both Gay and Bolt won their qualifying heats easily on Saturday and will have to make it through the semifinals today before the final event.
The reigning champions in women's volleyball, Misty May-Treanor and Kerri Walsh-Jennings, will also compete again today, after winning Saturday's match against the Netherlands. Today the undefeated pair will face Italy.