The weather was the story, however, with temperatures topping 105 degrees Fahrenheit in a heat wave that was predicted to last at least until Friday.
Nadal had to bear only one set's worth of the heat as, after Nadal claimed the first set 6-4, Australia's Bernard Tomic retired from the match with a groin injury.
Murray made short work of Go Soeda, winning 6-1, 6-1, 6-3 in 87 minutes with 32 winners against 13 unforced errors. Federer, with arguably the toughest draw among the big names, won 76 percent of the points on serve -- despite five double faults -- for a 6-4, 6-4, 6-2 win over James Duckworth.
Andreas Seppi, the No. 24 seed, took out Lleyton Hewitt 7-6 (7-4), 6-3, 5-7, 5-7, 7-5 in 4 hours, 18 minutes, making Australians 0-3 on Rod Laver Arena for the day. Tomic and Duckworth are also from Australia.
No. 13-seeded John Isner left the field because of an ankle injury. He was down 2-6, 6-7 (6-8) and Martin Klizan had won the first two points serving in the third set when Isner said the ankle pain left him unable to continue. He had fought through the injury last week in winning the ATP tournament in New Zealand
No. 5-seeded Juan Martin del Potro dropped a first-set tiebreaker but didn't lose his serve after the opening set in a 6-7 (1-7), 6-3, 6-4, 6-4 decision over Rhyne Williams.
Also, Jo-Wilfried Tsonga, seeded 10th, handled Filippo Volandri 6-5, 6-3, 6-3 while 11th-seeded Milos Raonic claimed a 7-6 (7-2), 6-1, 4-6, 6-2 win over Daniel Gimeno-Traver and 16th-seeded Kei Nishikori outlasted Marinko Matosevic 6-3, 5-7, 6-2, 4-6, 6-2.
Other seeded first-round winners Tuesday were 18th-seeded Gilles Simon, No. 22 -Grigor Dimitrov, 25th-seeded Gael Monfils, No. 26 Feliciano Lopez, 27th-seeded Benoit Paire and No. 31 Fernando Verdasco.