Russia's Aslan Karatsev, left, and Canada's Felix Auger-Aliassime shake hands after Karatsev won their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Feb. 14, 2021. The Australian Open continues but without crowds after the Victoria state government imposed a five-day lockdown in response to a COVID-19 outbreak at a quarantine hotel. (AP Photo/Andy Brownbill)