Under a blazing sun at Margaret Court Arena, Pegula’s stonewall defence left the hard-hitting Sakkari a hot mess and the American only grew in confidence as the match went on.

After Sakkari crumbled to lose the first set tiebreak 7-0, Pegula began swinging hard at the Greek’s serve and was rewarded with an early break in the second.

Sakkari battled to save a match point as Pegula served out but sent a defensive backhand wide to concede the match.

Pegula will play the winner of top seed Ash Barty and Amanda Anisimova for a place in the semifinals.

“That definitely was the best match I’ve played this year, this tournament for sure,” said the 21st seed.

“I was glad I was able to bring it today … I thought I returned really well, I really from the start wanted to put a lot of pressure on her serve.

“I knew I had to just take my chances but also be patient.”