The man Nadal beat in last year's U.S. Open final, No. 4 Daniil Medvedev, eliminated 2019 Australian Open quarterfinalist Frances Tiafoe of the U.S. in four sets. Also advancing: three-time major champion Stan Wawrinka, two-time French Open runner-up Dominic Thiem, No. 12 Fabio Fognini, No. 16 Karen Khachanov and No. 23 Nick Kyrgios, an Australian who spurred tennis players to contribute funds for wildfire relief efforts — and inspired TV analyst John McEnroe to pony up $1,000 per set Kyrgios wins the rest of the way in the tournament.