A second triumph at Melbourne Park for 2009 champion Nadal will break a three-way tie for the most major titles in the men's game, with the Spaniard nosing ahead of rivals Novak Djokovic and Roger Federer with a 21st Slam.
The 35-year-old repeatedly played down his chances in the leadup and during the past fortnight owing to a calamitous buildup due to a career-threatening foot problem and illness from contracting the COVID-19 virus.
Yet he has produced some incredible tennis to enjoy a 10-match winning run, picking up an ATP 250 title in Melbourne before the year's first major, and reach a 29th major final and his sixth in Australia.
"I just feel happy to be part of this amazing era of tennis, sharing all these things with another two players. That's it," Nadal said, adding that he was surprised to reach the championship match.
"In some ways it doesn't matter if somebody achieves one more or one less. We did amazing things and things that will be very difficult to equal. I don't think much about all this stuff."
Standing against him will be the world number two Russian - 10 years younger and a player who has already denied Djokovic a 21st major in the final of the U.S. Open in September.
Another win on Sunday will cement Medvedev's status as the leader of the next generation, who will give the 'old guard' a run for their money in an exciting year for the sport and end their iron grip on Slam titles.
Medvedev will be glad to play the role of dream wrecker once again.
"I'm gonna play again against one of the greatest. And what's funny, that again I'm going to play someone going for the 21st Slam," Medvedev said with a smile.
"I guess Rafa was watching (the U.S. Open final) near the TV ... I don't know who he was cheering for. I think Novak will be watching this one ... also!"
Medvedev will himself aim to become the first man, since tennis became professional in 1968, to win a second Grand Slam title immediately after claiming his first following his 2021 U.S. Open success.