Hope no-one inside Rod Laver Arena was wanting an early night - it's past 11pm in Melbourne now. And there is still a long way to go. They'd better grab a coffee at the change of ends.

Federer's serve is buckling again, Melzer forcing deuce before a couple of wobbly errors see Federer home. Storm, weathered.

Leon Smith
Great Britain Davis Cup captain on Radio 5 live sports extra

Roger is a little bit out of sync - but what do we expect? This is his first competitive match since Wimbledon. We should expect him not to be flowing. But fair play to Melzer, he's taken the game to him, been aggressive and serving well

This isn't what the masses wanted. The Fed Heads were hoping for a glorious return from their hero. They might be flustered but Rog isn't. He's never flustered. He rediscovers his servcie game, holding to love, before pushing Melzer to deuce in game two of the third set. But a stray backhand from the Swiss and an ace from his opponent sees the half-chance disappear down the drain.

Got it! Not the first set point, but the second. Roger Federer bats off Melzer's first effort, but is powerless to stop the second.

Little emotion from the Austrian qualifier as Fed hits the final ball of the second set into the net. Just a clenched first and icy stare up to his box. 

So, Melzer serves for the second set. Federer is up for the fight, keeping Melzer close at 30-30 when the Austrian sends a backhand drifting wide.

But Melzer - who we should say has been as high as eighth in the world before being hampered by age and injury - responds to earn himself a set point...

What a turnaround! Jurgen Melzer rattles off a quick service game then applies the pressure on Roger Federer. The 17-time Slam champion's serve - after being so dominant in the first set and a half - is creaking.

Two break points for the world number 296 - he only needs one. A classy backhand leaves Fed flummoxed and he is one away from levelling. Four games on the bounce for the Austrian...

A real scare for Wawrinka against the hard-hitting Klizan but the number four seed squeezes into round two after nearly three-and-a-half hours on Margaret Court Arena. 

There is one more match to come on the showcourt - Canada's Eugenie Bouchard, who reached the last four in Melbourne in 2014 on her way to a career-high fifth in the world that year, takes on Louisa Chirico of the United States.

Game on. Jurgen Melzer squanders his first break point, introducing ball to net with a weak backhand from the baseline. But he is gifted another chance when Federer also can't steer the ball over - this time Melzer converts.

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Stan's girlfriend Donna Vekic sums up her feelings quite nicely with this GIF...

Wawrinka moves within two points of victory but Klizan swipes at a shoulder-high ball deep behind his own baseline and sends it whistling into the far corner to level.

The 2014 champion hits back next point with a trademark cross court backhand that clips the line to bring up match point. And when the Slovakian dumps a forehand into the net on the next point, Wawrinka punches the air in delight.

Image source, AP

Finally we see some pressure put on the Federer serve. Break point for Melzer...

This match has been characterized by some strong serving. Another hold without reply for Austrian qualifier Melzer - the 11th win-to-love between the pair.

Wawrinka tags Klizan with a howitzer of a smash to drag himself back to 30-30 on his own serve. The Slovakian has clearly given up on a point after lobbing a half volley invitingly over the net but Wawrinka still drills the smash straight at his opponent and only the very edge of Klizan's racquet saves him from taking one in the nether regions.

Wawrinka hurdles the net to offer his apologies, which are accepted.

A bit of a momentum changer for the Swiss? Maybe. He wraps up the game to go ahead in the decider. 

Image source, EPA

Back to business for Roger Federer. His service game has been almost unblemished, leaving Melzer floundering with his variety. Not to mention his power. Another ace sets up the Swiss master at 40-0, a delicious backhand spinning out of Melzer's reach for the game. Roger celebrates with a change of racquet.

Image source, Getty Images

Respite for Jurgen Melzer. The Austrian qualifier has not won a Slam singles match since the 2015 US Open - I doubt it is going to happen today. But he earns a morale-boosting hold to love to get his side of the scoreboard ticking.

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While Stan Wawrinka finds himself in a sticky spot, his illustrious compatriot is cruising now. Roger Federer breaks to love in the first game of the second set, then digs a little deeper to hold his serve in deuce. Fed holds a clenched fist in the direction of his box, his facial expression as stoney as his gesture. I think that means he is happy. 

Fairly ridiculous scenes as Wawrinka first blazes a return forehand that has the crowd oohing, before Klizan answers with an equally thundering shot. Klizan snatches a break point and his supporters box goes crazy. They're cheering even louder when Klizan throws everything into a forehand that Wawrinka can't get near. 

Image source, EPA

No messing about. Another hold to love from the great man seals the opening set. And Federer seals it with a thumping ace. 

Other than the game where he broke Federer's serve, Melzer only managed to win one point on his opponent's serve. Wow. Just wow.

And Federer takes the first one. Now he is serving for the match after Melzer makes a mess a backhand return. The Austrian looks shell-shocked. Federer serving for the set...