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