After severe temperatures forced organisers to take the rare step of suspending play and closing the stadium roofs, the timing could not have been sweeter for the long-time rivals.
Just hours after Maria Sharapova slugged through three sets in brutal heat on an open Rod Laver Arena, Spain's Nadal stepped up with the roof closed to blitz world number 570 Thanasi Kokkinakis in less than two hours.
And Swiss Federer, playing simultaneously in a closed and air-conditioned Hisense Arena, produced a classic display as he took apart Slovenia's Blaz Kavcic in front of enraptured Melbourne crowd.
Following days of players fainting, vomiting and complaining about the heat, a suspension was finally announced at 2:00 pm and the full schedule did not resume until 6:00 pm.
Japan's Kei Nishikori was one of the early players but he dispatched Serbia's Dusan Lajovic 6-1, 6-1, 7-6 (7/3) to escape the heat in straight sets.
Frenchman Jo-Wilfried Tsonga made heavy weather of his first set against Brazil's Thomaz Belluci, which was played in the blazing sun, but he steamed through the rest of the match after the Hisense Arena roof rolled shut.
