Sisters Serena and Venus Williams are one win away from clashing in the Wimbledon final for a fifth time.
Top-ranked Serena has advanced to the semi-finals with a 6-4 6-4 quarter-final win over Anastasia Pavlyuchenkova while Venus advanced to the last four at Wimbledon for the first time in seven years with a 7-6 (7-5) 6-2 defeat of Yaroslava Shvedova.
Serena finished off Pavlyuchenkova with her eighth ace after just 73 minutes and next faces another Russian in the unseeded Elina Vesnina, who baet Slovakian 19th seed Dominika Cibulkova 6-2 6-2.
Continuing her extraordinary tennis renaissance, 36-year-old Venus is the oldest player to reach the Wimbledon last four since Martina Navratilova in 1994.
Sixteen years after winning her first of five crowns on London's hallowed grass courts, and five years after being diagnosed with Sjogren's syndrome, Venus will play Australian Open champion Angelique Kerber for a place in the final.
"We're just happy to be in the semi-finals. It's so cool, it's just great," Serena said.
"If I'm not in the final, obviously I want her to win so bad."
Champion in 2000, 2001, 2005, 2007 and 2008, eighth-seeded Venus will be contesting her 20th grand slam semi-final as she continues her pursuit of an improbable eighth major singles title.
The former world No.1 has won all eight previous semi-finals at Wimbledon, including the 2000 decider when she defeated 18-year-old Serena en route to her first Wimbledon crown.
After her breakthrough win at the Australian Open Kerber is now eyeing a second in six months after denying Romanian fifth seed Simona Halep 7-5 7-6 (7-2) in a rollercoaster encounter earlier that featured 13 breaks in 24 service games.
At 29, Kerber - a semi-finalist in 2012 too - believes she is playing the finest grasscourt tennis of her career.
She is the only woman not to have dropped a set yet in five matches this campaign.
With her victory, Serena also closed to within two wins of a seventh Wimbledon crown - and record-equalling 22nd grand slam title to match Steffi Graf's open-era benchmark tally.