Roger Federer hits a return against Steve Johnson during their men's singles match on Day 1 of the Australian Open in Melbourne on Monday. Photo: AFP

Roger Federer has ­never lost in the first round at the Australian Open since his debut 20 years ago, and the Swiss great kept his ­incredible record intact on Monday, attributing "old-school work ethic" for his Melbourne Park success.

The 38-year-old swatted aside Steve Johnson 6-3, 6-2, 6-2 to race into the second round, kick-starting his bid for a 21st Grand Slam title in immaculate style.

Federer said ahead of the tournament that he had low expectations at the year's opening Grand Slam after missing the warm-up ATP Cup to spend more time with his family.

It left him short of match practice, but it didn't show on Rod Laver Arena against the American.

He will next play either French qualifier Quentin Halys or Serbian Filip Krajinovic, admitting "I have to be careful." 

"Round-by-round, point-for-point mentality. I know other guys that are playing extremely well right now so I think it's just important to stay very calm about things."

Seeded three, Federer is gunning for not only a 21st Slam title but his seventh in Australia, having most recently tasted success at Melbourne Park in 2018.

His earliest exit in Australia since 2000 has been the third round, and the Swiss star said hard work was key to his longevity.

"At the end of the day, old-school work ethic, there is nothing wrong with that," he said. 

"I do believe if you're in a slump, not feeling well, whatever it may be, knowing how to train hard, when to train hard, with who to train hard, there is nothing wrong when it goes to those things. 

"And learning from your mistakes is key, as we remember our losses more than our wins. It's just important that when you do lose, you know, you really make the most of it, because it's actually an opportunity."

Despite his age, Federer remains a competitive force and won four singles titles last year.

But he failed to add another Grand Slam with his closest call coming in the Wimbledon final, where he lost a five-set epic to ­Novak Djokovic.

In contrast to his 2019 ­Major drought, Djokovic and Rafael ­Nadal won two apiece, with the Spaniard moving within one Slam title of Federer's record 20.