No 10 seed taken to first-set tie-break by Anastasia Potapova Concern for Ash Barty after world No 1 pulls out of doublesSerena Williams overcame a shaky start to book an
Australian Open fourth-round berth at Melbourne Park, while Ash Barty withdrew from the doubles competition amid concerns the world No 1’s thigh strain is more serious than she is letting on.
Seven-times champion Williams had to recover from 5-3 down and save two set points in the first set before recording a 7-6 (7-5), 6-2 victory over the former
Wimbledon junior champion on Friday.