Author: Sandra Harwitt, Special for USA TODAY Sports

Frances Tiafoe celebrated his 21st birthday with the biggest win of his career, knocking off Grigor Dimitrov to reach the quarterfinals in Melbourne.

Danielle Collins notched her third upset of a seeded player, pummeling No. 2 Angelique Kerber 6-0 6-2 in the fourth round.

Amanda Anisimova fell to Petra Kvitova in the fourth round, but the 17-year-old American’s breakout run has her primed for big things.