Serena and Venus Williams's bid for a third Olympic doubles gold medal is still on after they defeated Maria Kirilenko and Nadia Petrova of Russia this evening.
The first seven games of the match went with serve, with neither pair offering the other the chance of a break.
Kirilenko and Petrova staved off two break points in the next, managing to just hold on as the Williams sisters' intensity increased.
The Russians held off more break points at 4-5 down but couldn't do the same at 5-6, as the Americans broke to take the set.
The second set was much the same, with neither duo looking trouble on serve until the Russians buckled at 4-5 to see the Williamses into the final.
They will take on the fourth seeds from the Czech Republic, Andrea Hlavackova and Lucie Hradecka, in tomorrow's final, which is scheduled as the first match on Centre Court.