No. 19 seed Madison Keys scored the big upset on Day 9 of the Australian Open, defeating No. 6 Elena Rybakina 6-3, 1-6, 6-3 at Margaret Court Arena to advance to the tournament quarterfinals.

The No. 6 seed missed multiple break points to seize the advantage in the third set and Keys profited to move into the quarterfinals.

Elena Rybakina, the sixth seed at Melbourne Park, had looked in fine form in the early rounds, but came into Monday's clash with Madison Keys at Margaret Court Arena carrying a back issue

American Madison Keys upset sixth seed Elena Rybakina 6-3 1-6 6-3 in a roller-coaster match at Margaret Court Arena to march into the quarter-finals of the Australian Open on Monday and extend her win streak to nine matches this year.

She will next play Ukraine's Elina Svitolina, who beat Veronika Kudermetova 6-4, 6-1 earlier on Jan 20. Read more at straitstimes.com.

19th seed Madison Keys of the United States has reached the Australian Open quarter-finals for the fourth time in her career. She clinched a hard-fought win over sixth seed Elena Rybakina of Kazakhstan. The match lasted 1 hour and 49 minutes, ending with a scoreline of 6-3, 1-6, 6-3 in favor of Keys.

Madison Keys has upset former runner-up Elena Rybakina to set up an Australian Open quarter-final with inspired veteran Elina Svitolina.