The left-handed Californian Tien soaked up the applause at Margaret Court Arena after the biggest win of his young career following four hours and 48 minutes of seesawing action.
The feisty Russian, a three-time finalist in Melbourne, lost his cool in the third set before rallying to beat unheralded Thai Kasidit Samrej 6-2, 4-6, 3-6, 6-1, 6-2 on Rod Laver Arena.
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.
The left-handed Californian Tien soaked up the applause at Margaret Court Arena after the biggest win of his young career following four hours and 48 minutes of seesawing action.
The feisty Russian, a three-time finalist in Melbourne, lost his cool in the third set before rallying to beat unheralded Thai Kasidit Samrej 6-2, 4-6, 3-6, 6-1, 6-2 on Rod Laver Arena.
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.
