Simona Halep defeated one Williams sister at the Australian Open and now finds the other one standing in her way.
World number one Halep hit form in a 6-2 6-3 victory over Venus and will now take on Serena, who crushed a tearful Dayana Yastremska 6-2 6-1, in the fourth round.
Novak Djokovic dropped his first set of the tournament against Denis Shapovalov but recovered to win 6-3 6-4 4-6 6-0 while Naomi Osaka and Elina Svitolina both staged comebacks to make the last 16.
Djokovic crumbled in the fourth set after the floodlights appeared to be put on prematurely and the Serb's frustrations were there for all to see.
"Did you guys see the balls well?" he asked the crowd.
"I saw them well too," he said to a huge cheer. "It was completely unnecessary to turn on the lights.
"The explanation I got was for TV reasons. I hope the viewers enjoyed it."
Stat of the day
93,178 fans came through the doors of Melbourne Park, setting a new attendance record for the tournament by nearly 6,000 people.
Federer's awkward incident
He may be one of the most famous sports stars on the planet but even Roger Federer is not allowed into the men’s locker room without his accreditation.
As you can see below, through, he seemed to handle it fairly well.
Who’s up next?
Federer and Rafael Nadal face different generational tests in the fourth round on Saturday. Nadal takes on his old rival Tomas Berdych, back refreshed following injury, while Federer meets flamboyant 20-year-old Greek Stefanos Tsitsipas.
Maria Sharapova will look to follow up her big win over defending champion Caroline Wozniacki by defeating Australian hope Ashleigh Barty while 17-year-old Amanda Anisimova meets Petra Kvitova.