It was hard to assess the true state of the Spaniard's game as he swept aside world number 79 Victor Estrella Burgos 6-1 6-1 6-1 in the opening round of the Australian Open.
Channelling his early years with a sleeveless shirt, the muscular Mallorcan threw Mayer like a rag-doll around the Rod Laver Arena court for two hours and 38 minutes, pounding the world number 52 with a barrage of top-spin bombs.
But the Spaniard, who was beaten by Roger Federer in last year's final, got off to a flawless start and raced to victory over the 37-year-old.
The two met previous year on Nadal's route to winning the US Open, but the Argentine gave the world No 1 a scare in the first set with some strong serving.
Rafael Nadal resumes his march towards a 17th Grand Slam title on Wednesday after dispelling any lingering injury concerns in his first Australian Open match, with the Spanish star buoyed by feeling fit again.
"I'm through to the second round and that's a positive thing for me", Nadal said after losing only three games in his first-round romp.
"It will be a tough match for me especially after she beat Venus Williams".
Australian Open: Maria Sharapova into the second round after defeating Tatjana Maria
No. 9 Johanna Konta beat Madison Brengle 6-3, 6-1, handing the USA a 10th loss in 11 first-round women's matches. With temperatures heating up in Melbourne , the two Grand Slam winners wasted little time on court.
"This is a very important beginning for me; it was a good start", Nadal said.
After saying in his on-court interview he was happy to have girlfriend Ajla Tomljanovic with him at the event one journalist asked if she gave him support from the player's box. The Spaniard will face Leonardo Mayer not before 2:00 PM local time, for the fifth time in career.
France's 15th-seeded Jo-Wilfried Tsonga put in a solid performance, seeing off American Kevin King 6-4 6-4 6-1 to set up a second round clash with Canadian youngster Denis Shapovalov.
Edmund showed remarkable defiance to see off the South African 6-7 (4-7) 6-3 3-6 6-3 6-4, twice trailing by a set and then recovering from a 2-0 deficit in the final set.
Bulgaria's World No.3 Grigor Dimitrov got his Australian Open campaign off to an impressive start, proving too clinical for Austrian qualifier Dennis Novak, winning 6-3, 6-2, 6-1.
Like Dimitrov, the Dane is chasing her first Grand Slam title with her next hurdle Croatia's Jana Fett. Williams- a finalist in Melbourne a year ago - lost 6-3 7-5 to world number 78 Belinda Bencic.
Halep recovered from a 5-2 deficit in the first set.