After severe temperatures reaching 43.4 Celsius (110.1 Fahrenheit) forced organisers to take the rare step of suspending play on the outside courts and closing the stadium roofs, the big trio were able to play in air-conditioned comfort.
So just hours after Maria Sharapova slogged 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 Murray later took apart France's Vincent Millot, including a memorable fightback from 5-1 down in the final set, to show he remains a force to be reckoned with after back surgery.
They were three of the big winners after the four-hour heat shutdown,the first in five years, forced a hasty revision of the schedule with several matches extending past midnight.
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Just as players were returning to court, a freak rain and lightning storm erupted over Melbourne Park, further delaying the action.
Following days of players fainting, vomiting and complaining bitterly about the heat, a suspension was finally announced at 2:00 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 tough going of his first set against Brazil's Thomaz Belluci, played in the blazing sun, but he steamed through the rest of the match after the Hisense Arena roof rolled shut.