Roger Federer impresses on his return to action at the Australian Open

Federer had not played a competitive match in more than six months and while there were certainly signs of rust on Rod Laver Arena, the Swiss emerged unscathed with a 7-5 3-6 6-2 6-2 victory.

It remains to be seen how Federer's form, and fitness, reacts to tougher opponents but there should be some leeway too in the second round, where he now faces American qualifier Noah Rubin.

Federer played at the Hopman Cup, an exhibition event in Perth, earlier this month but this was his first official match since Wimbledon last year, after which he chose to sit out the rest of 2016 in a bid to overcome niggling injuries to his left knee and back.

"It was nice to be playing tennis again on a centre court like this, I couldn't be happier to be here now," Federer said on court afterwards.

"It's been a long road but I'm in the draw which is a beautiful thing.

"First rounds are never easy so I'm happy to live another day. Any match is a good match.

"Even if I had lost today it would have been good because I'm back on the court."

For all the talk of Andy Murray's new reign at the top of the world rankings, Novak Djokovic reasserting his dominance and even Rafael Nadal's latest resurgence, there is no doubt, however, who remains Melbourne Park's blockbuster attraction.

Federer's top billing here as the second night match on Rod Laver Arena spoke volumes about the 35-year-old's enduring popularity, with banners - one saying 'King Roger' - face masks and frequent shouts of adoration all emerging from the stands.

One moment in the second set saw Melzer begin walking to the change of ends mid-rally, even before Federer had completed his winner, and it was tempting to think the crowd would have been happy for every point to end with a similar submission.

Instead, Melzer offered Federer exactly the sort of examination he would have hoped for - stiff enough to test the body and find the groove - but flimsy enough in the key moments to ensure progress always felt likely.

There were glimpses of magic - the touch volleys, looping lobs and leaping returns - but also cobwebs to blow out - backhands into the net, missed forehands and dodgy spells of serving.

At two hours and six minutes, however, Federer was spared both extended time on the court and also the sweltering heat players had endured earlier in the day.

Murray's match against Illya Marchenko, only three sets but lasting two hours and 47 minutes, took place in temperatures reaching 32 degrees Celsius.

Melzer took a 4-2 lead in the opening set but after a slow start, Federer found his stride, breaking once and then again, decisively at 6-5.

He carried his momentum into the second for a 3-1 advantage but then proceeded to lose five games in a row, as Melzer clinched the set and levelled up.

Any suggestion of an upset, however, was soon dispelled, as Federer sailed through the last two sets without offering up a single break point. When Melzer missed a final forehand, the job was complete.