Ruthless from Roger Federer. An ace to seal the third set.

Wonderful from the defending champion, waltzing round a short ball to tuck it away on his forehand side.

Big serves follow. That's 40-0.

Punchy and potent from Marin Cilic, he holds.

Federer attacks a top-spin Cilic second serve, but can only coax it into the net, his next return follows it into the same spot and the a miscued forehand drifts wide.

40-0.

The placard-waving Roger Federer fans are in full voice inside Rod Laver Arena.

Marin Cilic is serving to stay in the third set.

Roger Federer under-cooks a backhand slice from deep, not for the first time today.

The defending champion then leaps over a Marin Cilic return, that's long and he holds.

Inch-perfect from Federer, who picks out the top corner of the service box with an ace. Postage stamp stuff.

The Swiss follows up with a remarkable return on the run, whipping and curling it inside the line and a shocked Cilic can't get it back. Wow!

Another ace, that's 40-15.

Russell Fuller
BBC tennis correspondent at Melbourne Park

You know when Federer has the break because of the noise inside the arena.

Cilic leans back and pops a forehand wide, Federer breaks and screams "come on" to boot.

Image source, Reuters

The first goes begging, deep into the net with a backhand that warrants a Federer head shake.

Image source, Reuters

Pat Cash
Former Wimbledon champion on BBC Radio 5 live

That's a good game from Federer. He's made Cilic play everything.

Another mistake from Cilic, cracking the net with a backhand as Federer earns three break points.

That's uncharacteristic from the Marin Cilic we've seen recently, firing a short ball into the net with time to pick his spot.

Federer draws his opponent to and fro, before Cilic attempts to come to the net but can't get enough on his backhand volley.

0-30.

Pat Cash
Former Wimbledon champion on BBC Radio 5 live

BBC Radio 5 live has been discussing whether Roger Federer gets a favourable schedule in Melbourne...

Is it a tennis tournament or is it about TV and money? I've said this is a festival with a tennis event.

Tennis Australia are an event organisation. They put a tennis tournament inside a festival - it's like a rock concert.

Their priority is TV and money. It should be even for players and it's not.

Is it right or wrong? I don't know.

Cilic gambles, and it pays off - he guesses the Federer serve is coming wide and latches on to it with forehand aplomb.

Federer closes out. The third set remains on serve.

Image source, EPA

Roger Federer gives little away in the emotional stakes. Is he nervous? Excited? Tired? Who knows...

He's found a rejuvenated Marin Cilic at the opposite end of Rod Laver Arena since steaming through the first set, but the Swiss cruises to 40-15 in his service game.

Image source, Reuters

Pat Cash
Former Wimbledon champion on BBC Radio 5 live

Is Cilic a nice guy? He's almost too nice! He's very popular.

Zinger. A scorcher of an ace from Marin Cilic, who also gets the better of the following rally as Federer wraps a backhand against the net.

Cilic holds.

Image source, EPA

Pat Cash
Former Wimbledon champion on BBC Radio 5 live

Gone are the unforced errors from Cilic. He's hitting the ball so much cleaner now, but it's a case of whether he can keep the intensity up.

If he relaxes a fraction he's in trouble.

"Living on a Prayer" rings out between the change of ends, but I reckon we're not quite half way there in this one...

Smart forehand winner from Cilic, sending Federer one way and then placing the ball the other, with the defending champion sending a backhand return beyond the baseline off the next point.

30-15.