Federer has only twice been extended past the two-hour mark in reaching his seventh final in Melbourne and even those two matches this week, against unseeded Marton Fucsovics and Tomas Berdych, were straight-sets wins. 

“I can’t believe how fast now the week has turned out to be,” the 36-year-old said after Chung Hyeon, his semi-final opponent, retired with foot blisters 62 minutes into the game. 

One local bookmaker says it has already paid out £287,000 to punters who backed world No2 Federer to retain the title he won in a thriller against Rafael Nadal last year.

Hopes of a repeat of that epic match were dashed when Nadal retired hurt in the fifth set of his quarter-final with Cilic on Tuesday, although nothing should be taken away from the Croatian sixth seed, who crunched a mind-boggling 83 winners.

A top-10 regular, Cilic will bring an arsenal of heavy artillery to Rod Laver Arena today, when temperatures in Melbourne are expected to be in the high 30s with high humidity – the most extreme conditions Federer has faced during two weeks in which he played only one match during the day. 

Cilic has a 1-8 head-to-head record against Federer. 

His sole victory came in the US Open semi-final in 2014. 

Caroline Wozniacki won her first Grand Slam title at the 43rd attempt with an emotional victory over Simona Halep.

The Dane’s hard-won 7-6, 3-6, 6-4 triumph means she will overtake Halep as world No1 exactly six years since she last held top spot. 

She said: “This is a very emotional moment. It’s been an incredible two weeks.”