Serena Williams again was at her dominating best when she beat Spain's Carla Suarez Navarro 6-0, 6-0 to reach the semi-finals.
China's Li Na ended the fairytale run of Russia's Ekaterina Makarova, after she beat her 6-4, 6-7, 6-2.
Belarus' Victoria Azarenka came through a tough challenge from Serbia's Ana Ivanovic and won her match 4-6, 6-3, 6-4.
Li Na and Serena will face-off for a pace in the finals.
