American duo Kerri Walsh Jennings and Misty May-Treanor remain on target for a third consecutive Olympic beach volleyball gold after defeating Italy to progress to the last four.
Walsh Jennings and May-Treanor beat Marta Menegatti and Greta Cicolari 21-13 21-13.
They will play the Chinese duo of Xue Chen and Zhang Xi in the semi-final.
Xue and Zhang won 21-18 21-11 against Austrian sisters Stefanie and Doris Schwaiger.
In other quarter-final action, Larissa Franca and Juliana Felisberta of Brazil beat Germany's Laura Ludwig and Sara Goller 21-10 21-19.
They will play the USA's number two team of Jennifer Kessy and April Ross, who secured a 25-23 21-18 win against Czech duo Marketa Slukova and Kristyna Kolocova.