There were bizarre scenes on Rod Laver Arena as Anastasia Potapova double faulted five times in a single game with Serena Williams left to watch on stunned.
Williams battled her way into the last 16 after what was a scrappy 7-6(5) 6-2 win over the Russian, but it could have been very different had Potapova kept her composure.
Serving at 5-3 up after a very impressive start to the match, the 19-year-old from Saratov totally lost her cool, and her serving technique, at what was a crucial point in the match.
Williams, pursuing her 24th Grand Slam in Melbourne, could only watch on in bewilderment at the developing disaster for her young opponent.
"What's wrong?!" Potapova screamed up at her box in frustration as her serve fell apart when she needed it most.
'What's wrong?!' - Serena stunned as Potapova double faults FIVE times in one game
It was tough to watch as the Russian battled back time and again through deuce, only for her serve to continue to ruin her progress in the match.
Serena, the 10th seed, improved as the contest progressed and will now take on the in-form Aryna Sabalenka in the next round.
“It feels good to be in the fourth round," she said after the victory, which was anything but easy or straightforward for the American.
"It felt good to get through that match, it felt like I didn’t come out of the starting blocks like I would’ve liked to since I’ve been playing here but it’s about surviving and playing better every round."
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