Five-time champion Venus Williams won in her 100th singles match at Wimbledon to knock out French Open winner Jelena Ostapenko and reach the semi-finals.
Williams earned a 6-3 7-5 victory against the 20-year-old Latvian in one hour and 13 minutes on Centre Court.
She will play either Britain's Johanna Konta or Simona Halep in the last four.
Meanwhile, Garbine Muguruza reached her second Wimbledon semi-final with a powerful straight-set victory over seventh seed Svetlana Kuznetsova.
American Williams, 37, is the oldest player to reach the last four since Martina Navratilova in 1994.
Williams, competing at her 20th Wimbledon, is just one victory away from her ninth final at SW19 - eight years after her last appearance.