Novak Djokovic, Coco Gauff roll to Australian Open's 4th round. Naomi Osaka retires due to injury and Jessica Pegula was upset in the third round.

An "emotional" Paula Badosa of Spain stunned the world number three American Coco Gauff 7-5, 6-4 on Rod Laver Arena and will face defending champion Aryna Sabalenka or Anastasia Pavlyuchenkova in the last four.

The number of Americans in the field has dwindled, but Coco Gauff continues to get the job done on the court. The No. 3 seed dropped her first set against Belinda Bencic, but roared back to conquer the second and third sets, winning 5-7, 6-2, 6-1 in two hours and 26 minutes.