The United States' Kerri Walsh Jennings and Misty May-Treanor, the two-time defending Olympic women's beach volleyball champs, defeated the Netherlands' Marleen van Iersel and Sanne Keizer in the first round of elimination play on Saturday. The Americans won the first set with a commanding lead over the Netherlands, 21-13. Walsh Jennings and May-Treanor kept the momentum going in the second set, defeating the Netherlands 21-12. Walsh Jennings and May-Treanor advance to the quarterfinal round of the Olympic tournament, still undefeated in Olympic play. They will face Italy's Marta Menegatti and Greta Cicolari on August 5. The United States' Jake Gibb and Sean Rosenthal advanced to the quarterfinal round of the men's beach volleyball tournament. The Americans defeated Russia's Konstantin Semenov and Sergey Prokopiev in two sets, 21-14 and 22-20. Gibb and Rosenthal will face Latvia's Martins Plavins and Janis Smedins in the men's quarterfinal match on August 6.