A third Italian will be in action as fifth seed Lorenzo Musetti plays American ninth seed Taylor Fritz to set up a quarter-final clash with Novak Djokovic, while Jessica Pegula and Madison Keys meet in an all-American battle.
Swiatek looking for semi-final berth
Home favourite Inglis is the only qualifier still in the mix, reaching the fourth round of a Grand Slam for the first time after her third-round opponent Naomi Osaka pulled out due to injury.
Six-times Grand Slam winner Swiatek has been clinical in the pursuit of her first Australian Open title, dropping only one set.
But 28-year-old Inglis, who went through three-hour battles in the first two rounds, will hope she can put up a better fight against Swiatek after losing in straight sets to her nearly five years ago.
“I’ll get out there... and do everything I can to take it up to Iga on Monday. It’ll be really fun," Inglis said.
Italian duel for Sinner
Italian 22nd seed Darderi nearly had to pull out from a TV interview due to a cramp he experienced live on air.
Darderi battled Karen Khachanov for almost three-and-a-half hours on Saturday as temperatures reached 36 degrees Celsius. Later, while appearing on the Australian Open's Blue Zone broadcast, he suddenly grimaced and grabbed his leg in pain.
The 23-year-old, who has reached the fourth round of a major for the first time, faces Sinner, who also experienced cramps during his third-round clash with Eliot Spizzirri.
“I struggled physically a bit today. I got lucky with the heat rule, they closed the roof. I took my time, as the time passed, I felt better," said Sinner, who is eyeing his third straight Australian Open title.
“Of course, there are going to be days where you don't find a way... if you are in a court thinking in a negative way, most likely more negative things can come towards you. I try to stay calm even in a moment like this.”
Injured Fritz faces Musetti challenge
Fifth seed Musetti is proud to be part of history, as three Italians, including Sinner and Darderi, have reached the Australian Open's fourth round for the first time.
"I feel pretty proud to be part of this trio... it’s my first time, so I’m really, really happy," said Musetti, who has reached the semi-finals at the French Open and Wimbledon but had never advanced to the fourth round at the Australian Open.
Musetti and Fritz won three times each in their previous six meetings, but the American ninth seed may be at a disadvantage after a gruelling four-set battle with Stan Wawrinka.
"To be honest, today wasn’t a great day for me physically," said Fritz.
“The other day I was starting to feel really confident, maybe even overconfident about my knee. But right now it feels pretty bad, and it didn’t feel great during the match either."
The winner will face Djokovic, who progressed to the quarter-finals after his fourth-round opponent Jakub Mensik withdrew due to injury.