Serena and Venus Williams [ Images ] were sent packing from the women's doubles at the Australian Open [ Images ] on Tuesday, beaten 3-6, 6-4, 6-2 by former champions Yan Zi and Zheng Jie [ Images ] of China in the quarter-finals.

The American sisters, unseeded this year, looked on course for victory when they won the first set but were then completely outplayed by the seventh seeds in a match lasting just under two hours.

Zheng and Yan, winners at Melbourne [ Images ] Park in 2006, used their greater doubles experience to superb effect as the match wore on.

After missing one match point, they clinched a deserved victory to line up a semi-final against 12th seeds Victoria Azarenka [ Images ] of Belarus and Israel's Shahar Peer.

It was Serena's second defeat in the space of a few hours after she lost 6-3 6-4 to Serbian third seed Jelena Jankovic [ Images ] in the singles quarter-finals.