Adelaide: Former Australian Open champion Angelique Kerber sustained a lower back injury and retired from her Adelaide International match on Wednesday.
The former world No. 1 trailed 6-2, 2-0 in her match against Dayana Yastremska when she stopped playing. Kerber, who won the Australian Open in 2016 and also has Wimbledon and US Open titles, had on-court medical help for the injury and then retired.
Kerber lost in the first round to Sam Stosur last week at the Brisbane International.
