The final match of the day saw American Learner Tien, playing in his first major outside of the U.S. Open, upset No. 5 seed Daniil Medvedev in a five-set classic, 6-3, 7-6, 6-7, 1-6, 7-6, that ended at 2:54 a.m. local time. Medvedev had reached three of the past four Australian Open finals, but could not fend off a ferocious Tien.

Defending champ Jannik Sinner drops set for first time since October, but rallies for win; American Danielle Collins plays villain while advancing.

Jannik Sinner has announced that he will part ways with his coach Darren Cahill at the end of the season. The Australian, who joined Sinner's team in July 2022, will conclude the 2025 campaign before stepping back from full-time tennis.

Twelve seeded players are in action Thursday (7 p.m. ET Wednesday night )at the Australian Open, including No.2 Iga Swiatek and No.4 Jasmine Paolini.

Iga Swiatek has made it to round 3 with relative ease, dispatching Sramkova 6-0, 6-2. Ons Jabeur was able to overcome a wobble in the first set to beat Camila Osorio and make it to the next round. World No.

Iga Swiatek rushed through her first set in 26 minutes and completed her 6-0, 6-2 second-round win over Rebecca Sramkova in an hour at the Australian Open

Highlights of the fifth day of the Australian Open on Thursday (all times GMT): 1554 TEENAGER TIEN STUNS MEDVEDEV American qualifier Learner Tien held his nerve in a battle that lasted four hours and 49 minutes to stun Russian fifth seed Daniil Medvedev,

Spots in the second week of the Australian Open are on the line over the next couple of days, as players look to advance to the Round of 16. Aryna Sabalenka continues her quest for an outstanding third straight Australian Open title.