Jannik Sinner advanced to the Australian Open quarter-finals, overcoming illness, while Lorenzo Sonego ended Learner Tien's dream run. Madison Keys surprised Elena Rybakina, and Elina Svitolina uplifted Ukraine by defeating Veronika Kudermetova.

Day nine of the Australian Open saw Lorenzo Sonego and Elina Svitolina advance to the quarter-finals with impressive wins. Jannik Sinner overcame a medical timeout to beat Holger Rune, while Madison Keys stunned Elena Rybakina.

Jannik Sinner battled through illness to reach the quarter-finals of the Australian Open on Monday as his Italian compatriot Lorenzo Sonego ended teenager Learner Tien's fairytale run.

Elina Svitolina of Ukraine gestures during her fourth round match against Veronika Kudermetova of Russia at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 20 ...

MELBOURNE, Australia (AP) — Elina Svitolina rallied from 4-1 down and took 11 of the next 12 games in a 6-4, 6-1 victory over Veronika Kudermetova on Monday to reach the Australian Open ...

He has an easy quarterfinal matchup on paper against Lorenzo Sonego ... 7-5 No. 26 Elina Svitolina def. Veronika Kudermetova, 6-4, 6-1 Iga Swiatek, Madison Keys and Elina Svitolina are back ...

Advertisement Article continues below this ad Lorenzo Sonego ... Elina Svitolina (28), Ukraine, def. Veronika Kudermetova, Russia, 6-4, 6-1. Advertisement Article continues below this ad Madison ...

But American teenage qualifier Learner Tien's fairytale run is over after he suffered a thigh problem in a four-set defeat to Italy's Lorenzo ... Svitolina beat Veronika Kudermetova -- then ...