The Madison Keys who will play two-time defending champion Aryna Sabalenka for the title at the Australian Open on Saturday night is not the same Madison Keys who was the runner-up at the U.S.

Madison Keys won her first ever grand slam title on Saturday, stunning two-time defending champion and world No. 1 Aryna Sabalenka 6-3 2-6 7-5 in a thrilling Australian Open women’s final.

Madison Keys has learnt plenty since her last, and first, grand slam final – mainly to embrace the prospect of being “uncomfortable 99 per cent of the time”.

It is Keys's first major title, having reached a second Grand Slam final eight years after her first in New York. She lost on that occasion to Sloane Stephens

An American woman is a champion once again. After having to face the two best players in the world -- Iga Switaek and Aryna Sabalenka -- Madison Keys has claimed her first Grand Slam title at the Australian Open. Keys outlasted Sabalenka in the final on Saturday over three sets to accomplish the feat.

Madison Keys upset Aryna Sabalenka in the Australian Open final to clinch her first Grand Slam title. Read more on Boston.com.

Madison Keys beat Aryna Sabalenka 6-3, 2-6, 7-5 in the Australian Open final at Melbourne Park Saturday. The No. 19 seed prevailed over the No. 1 seed in a fast-paced match, ultimately decided by Keys’ incredible serving in the first set,

American underdog Madison Keys finally gets her hands on a Grand Slam trophy after holding off defending champion Aryna Sabalenka to win the Australian Open.

Keys' last and only other appearance in a grand slam final was eight years ago, where fellow American Sloane Stephens won the match against her. Related: Naomi Osaka & More Female Tennis Stars Reflect on the WTA's Legacy as U.