Ukraine's Elina Svitolina hits a backhand return to United States' Jessica Pegula during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Feb. 15, 2021.(AP Photo/Andy Brownbill)

Spain's Rafael Nadal celebrates his win over Britain's Cameron Norrie in their third round match a the Australian Open tennis championships in Melbourne, Australia, Saturday, Feb. 13, 2021. (AP Photo/Andy Brownbill)

United States' Jessica Pegula serves to Ukraine's Elina Svitolina during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Feb. 15,2021.(AP Photo/Andy Brownbill)