Despite the windy conditions, Williams improved to 5-2 on the season, which includes a third round win on Monday over sister Serena, who was making her return to the WTA after having a baby
A wildly unpredictable match veered one way, then the other, before the Romanian ended Kerber’s resistance on her fourth match point in a spellbinding deciding set on Thursday.
Serena overcame a shaky start to land an unprecedented seventh Open title and open-era record 23 grand slam singles crown with an emotional 6-4 6-4 triumph on Saturday
The 35-year-old American served up 10 aces and thumped 25 winners over 75 minutes on Rod Laver Arena to join sister Venus in the last four, where she will play 34-year-old Croatian Mirjana Lucic-Baroni
After witnessing Serena Williams lose to Karolina Pliskova, Kerber was aware that victory over her Danish opponent would see her overtake the American in the standings but she showed little nerves on the Arthur Ashe Stadium court
The fourth seed will be aiming to become the first German woman since Steffi Graf 20 years ago to lift the Wimbledon singles crown