Serena Williams of the USA in action during the women's singles match between USA and Greece on day three of the Hopman Cup tennis tournament at Perth Arena in Perth, Australia, 31 December 2018. EPA-EFE/TONY MCDONOUGH Frances Tiafoe of the USA falls over during the men's singles match between Frances Tiafoe of USA and Stefanos Tsitsipas of Greece on day three of … [Read more...] about Photo Gallery Of Serena Williams, Grigor Dimitrov, & More At The Hopman Cup Tennis