Medvedev still leads their head-to-head 7-6, although the Italian Sinner has won six of their last seven meetings.
Top seed Swiatek, who won the title two years ago, showcased her all-court game in a straightforward 6-4, 6-1 win over Russian Liudmila Samsonova to open the evening session at Arthur Ashe Stadium and warned she was only going to improve.
The Russian looked out of sorts early on Centre Court as he lost the first set.
Medvedev, a semi-finalist last year, hit 16 aces in his 6-3, 6-4, 6-2 win over Aleksandar Kovacevic of the United States.
De Minaur had never got past the second round at the tournament before this year, winning just three of 10 matches.
Italy's Jannik Sinner destroyed defending champion Daniil Medvedev 6-1, 6-2 in just 69 minutes on Friday to reach the final of the ATP Miami Open, where he will take on Grigor Dimitrov.
Daniil Medvedev returned to action for the first time since his Australian final defeat on Tuesday with a straight sets win over Alexander Shevchenko in Dubai.
Medvedev feels ready to get back on court after spending the last seven days training in Dubai.
Since Stan Wawrinka won his only title in Melbourne in 2014, Novak Djokovic has picked up six trophies, Roger Federer has won two and Rafael Nadal has won one.
American Sebastian Korda reached the quarter-finals of a Grand Slam for the first time on Sunday after defeating Poland's Hubert Hurkacz 3-6, 6-3, 6-2, 1-6, 7-6 (10-7) at the Australian Open.
Sebastian Korda says he's "the worst athlete" in his high-achieving sporting family, but with a little help from tennis legend Andre Agassi the rising American is working hard to change the dynamic.
Five top contenders for the men's title at the Australian Open, which starts on Monday:
Novak Djokovic overcame an injury scare midway through his match against Daniil Medvedev on Saturday to mow down the Russian 6-3 6-4 and storm into the Adelaide International 1 final, where he will take on unseeded American Sebastian Korda.
Former world number one Daniil Medvedev set up an Adelaide International semi-final against either Novak Djokovic or Denis Shapovalov Friday with a command performance in the countdown to the opening Grand Slam of the year.
Daniil Medvedev on Sunday admitted he would rather be playing at the mixed teams United Cup than the Adelaide International, but the Russian intends to make the most of the season-opening event.
Australia's Nick Kyrgios sent defending champion Daniil Medvedev tumbling out of the US Open on Sunday as US teenager Coco Gauff reached the quarter-finals for the first time.
World number one Daniil Medvedev maintained his strong start to his U.S. Open title defence on Wednesday, dispatching France's Arthur Rinderknech 6-2, 7-5, 6-3 in the Arthur Ashe Stadium to reach the third round.
A talented men's field is set for the 2022 U.S. Open, beginning on Monday. Flushing Meadows hosts the event with Rafael Nadal operating as the headline-grabbing player on the men's side.
Rafa Nadal said it was sad news that his great rival Novak Djokovic will be missing from the U.S. Open, adding that the absence of a player of the Serbian's calibre was an important miss for the hardcourt Grand Slam.
