Coco Gauff surged into the second round in Melbourne with a 7-6 (7/5), 6-3 victory over Venus Williams and will play unseeded Romanian Sorana Cirstea next.
Venus Williams pulled out of the season-opening Brisbane International on Wednesday after a "setback" during practice.
Danielle Collins rallied back from 3-5 down in the opening set, winning a whopping nine games in a row to go up 7-5, 5-0 against Venus Williams.
Carlos Ramos will not officiate any US Open matches involving Serena or Venus Williams.
Cori Gauff, 15, is not content with just beating five-time champion Venus Williams -- now she wants to win the Wimbledon title.
15-year-old Cori Gauff pulled off a major upset at Wimbledon, as she knocked out five-time champion Venus Williams 6-4, 6-4.
Roger Federer produced an excellent all-round performance despite being tested by the world number 103 Filip Krajinovic.
Venus Williams rallied from a set and two breaks down to topple third-seeded Petra Kvitova 4-6, 7-5, 6-4 at Indian Wells.
Serena Williams won her 23rd major Down Under two years ago while two months pregnant.
Novak Djokovic defeated Jo-Wilfried Tsonga 6-3, 7-5, 6-4 in straight sets.
The pressure on the reigning French Open champion will only increase in her next round.
Serena Williams won her 23rd title and seventh at Melbourne Park while eight weeks pregnant two years ago.
The family of 78-year-old Jerome Barson had filed a wrongful death suit against Williams following the June 2017 crash in Palm Beach, Florida.
Serena Williams was all business for the highly anticipated all-Williams clash under the lights on Arthur Ashe Stadium.
Serena Williams enjoys a 17-12 head-to-head superiority against her sister Venus.
Top seed Halep took no prisoners against Williams, blitzing the 38-year-old American 6-2, 6-2 in just 71 minutes to reach the quarter-finals.
Maria Sakkari won 6-4, 7-6 (7/2) against former world number one Venus Williams.
Kiki Bertens, who reached the French Open semi-finals in 2016, had never before been past the Wimbledon third round.