Updated

There are no American teams left in the Olympic men's beach volleyball tournament.

The last remaining U.S. pair, Jacob Gibb and Sean Rosenthal, fell in the quarterfinals Monday to Latvia's Martins Plavins and Janis Smedins despite winning the first set.

Plavins and Smedins went on to win 19-21, 21-18, 15-11 and will meet Brazil's Alison Cerutti and Emanuel Rego in the semifinals Tuesday.

Americans Todd Rogers and Phil Dalhausser, the 2008 gold medalists, lost in the first round of the knockout stage to Italy's Paolo Nicolai and Daniele Lupo.

But the U.S. is still guaranteed at least one medal in beach volleyball here.

Two-time reigning Olympic champions Misty May-Treanor and Kerri Walsh Jennings and another U.S. pair, April Ross and Jennifer Kessy, made the semifinals of the women's tournament. They will both play Tuesday.

Cerutti and Rego needed three sets to top Poland's Mariusz Prudel and Grzegorz Fijalek 21-17, 16-21, 17-15 in one hour Monday.

The other men's semifinal Tuesday will pit Germany's Julius Brink and Jonas Reckermann against Reinder Nummerdor and Rich Schuil of the Netherlands. Brink and Reckermann beat Brazil's Ricardo Santos and Pedro Cunha 21-15, 21-19 while Nummerdor and Schuil topped Nicolai and Lupo 21-16 21-18.