Ashleigh Barty has all but secured the year-end world No.1 ranking with a steely comeback victory in her opening match at the WTA Tour Finals in Shenzhen.

Unless disaster strikes and she can’t walk on court again this week and Karolina Pliskova takes the title, Barty’s 5-7 6-1 6-2 win over Belinda Bencic on Sunday night earned the 23-year-old a place in tennis history as the first Australian woman to finish a season in top spot since rankings were introduced in 1973.

It is a feat that not even grand slam legends Margaret Court or Evonne Goolagong Cawley ever managed.