Serena Williams is a hot favourite to beat Maria Sharapova and claim her 19th grand slam title.
But what will need to go right for her to do so, and what can the Russian do to counter the powerful American?
We assess the keys to victory.
Williams' serve
If Williams serves at her best, it will take something special for her to be beaten. Williams has served 70 aces at the tournament, putting her top of that list by a long way. Her power and placement mean she holds regularly, and puts plenty of pressure on her opponent to do likewise.
Williams' start
Flat and lacking energy is how Williams has started several of her matches in Melbourne, including dropping the first sets against Elina Svitolina and Garbine Muguruza. She cannot afford a slow start against Sharapova.
Sharapova's mentality
There must exist demons of 15 straight losses to an opponent, a run during which you have won just three sets. Sharapova is as mentally strong as they come, and she will need all that strength in the big moments.
Williams' desire
It would seem a strange query of a player who has reached the final, but Williams has talked down the importance of winning the title regularly. She may just be trying to ease the pressure on herself, but Williams says she can "just relax and have fun".
Baseline control
In their semi-final, Madison Keys showed the power to trouble Williams. Sharapova possesses less but enough to cause Williams problems – if she can maintain control and play with good margins. Over-hitting and playing too close to lines puts players in trouble against Williams, and Sharapova needs to avoid falling into that trap.