Complex sentence: Williams was the oldest player to reach the final since Martina Navratilova in 1994, and played her 100th singles match at Wimbledon when she defeated Jeļena Ostapenko in the quarterfinals.
Split into simpler sentences: Williams was the oldest player to reach the final since Martina Navratilova in 1994. Williams played her 100th singles match at Wimbledon when she defeated Jeļena Ostapenko in the quarterfinals.