Top seeds Lisa Raymond and Liezel Huber look on course for a medal in the women's Olympic doubles following a straight-sets win over the Russian pairing of Elena Makarova and Elena Vesnina at Wimbledon.
Despite dropping serve twice in an unpredictable opening set, the Americans rallied to win 6-3.
They asserted their dominance instantly in the second with a break over the sixth seeds and went on to break again to take the second 6-3 again.
Czech fourth seeds Andrea Hlavackova and Lucie Hradecka could be waiting for the Americans in the semis, but they will first have to play the winners of the match between Chia-Jung Chuang and Hsieh Su-wei of Taiwan and Flavia Pennetta and Francesca Schiavone of Italy.