Postpublished at 08:48 Greenwich Mean Time 23 January 2018
David Law
Radio 5 live sports extra commentator at Melbourne Park
Cilic has excellent ground strokes. For a man of his size, he moves well. He can cause Nadal problems.
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Caroline Chapman
David Law
Radio 5 live sports extra commentator at Melbourne Park
Cilic has excellent ground strokes. For a man of his size, he moves well. He can cause Nadal problems.
*Nadal 3-3 Cilic
BANG!
With an overhead smash, Marin Cilic saves five break points to hold and level.
Gigi Salmon
Radio 5 live sports extra commentator at Melbourne Park
There have been seven unforced errors on Cilic's forehand so far.
*Nadal 3-2 Cilic
A seventh unforced error from Cilic gives Nadal ANOTHER break point.
Fifth time lucky? Nope. Out again. Deuce number seven.
Now Cilic has the advantage. What an almighty hold this would be!
*Nadal 3-2 Cilic
Right then, can Nadal do it on break point four?
Nope. He's gone wide again.
Deuce #6.
David Law
Radio 5 live sports extra commentator at Melbourne Park
Marin Cilic is going to have to play lights out tennis - the sort that saw him beat Roger Federer at the US Open in 2014. And that is a big ask. In many ways, Nadal looks as good as ever to me. There are no signs of the knee injury that caused him to struggle last year.
*Nadal 3-2 Cilic
A flick of the wrist on the forehand brings up another break point for Rafael Nadal - his third in this game.
He screws the ball long and we're going back to deuce for the fifth time.
*Nadal 3-2 Cilic
Marin Cilic coughs up the first double fault of the match and gifts Rafael Nadal his first break opportunity.
It's saved with a colossal serve which Nadal returns into the net.
The Spaniard brings up another break point. That goes amiss to when Nadal nets after a baseline battle.
We continue.
*Nadal 3-2 Cilic
The TV cameras have picked up Marin Cilic's serving ticks. As he bounces the ball about 18 times, his back foot (his right one) beats in time with the ball drop.
The world number six is pushed all the way to deuce again, but luckily for him Nadal backhands wide to give the Croat the advantage.
But then Cilic thumps the net. Back to deuce.
Leon Smith
GB Davis Cup captain on BBC Radio 5 live sports extra
Cilic hits the ball flat. If he gets good depth, it's more difficult for Nadal. He prefers the ball higher so he can use more top spin on his forehand
Nadal 3-2 Cilic*
Rafael Nadal must be really frustrating Marin Cilic here.
Cilic is finding some brilliant returns, but somehow Nadal responds every time - mixing up backhand and forehand winners.
It's a little more testing this time for the world number one, but he holds to 30.
Gigi Salmon
Radio 5 live sports extra commentator at Melbourne Park
Nadal must love facing Cilic. He has so much time to sort himself out when Cilic is serving.
*Nadal 2-2 Cilic
Cilic comes into the net to slam the ball on to the baseline and then serves it out with an ace.
He's come through that test in style.
*Nadal 2-1 Cilic
A booming ace from Cilic to open the next game. These two are mirroring each other!
That is until Nadal starts pinning his opponent back. We're at 30-30 after a lovely drop shot from the Spaniard.
Cilic finds the corner with a backhand to edge ahead, before planting into the net for deuce.
The first real test on serve for the Croat.
Nadal 2-1 Cilic*
The crowd throughly enjoy a maiden ace from Rafael Nadal, and then they coo over a fantastic pick-up volley from Marin Cilic, which sees the Spaniard lose his first point off his serve.
Two forehands up the line gives Rafa the hold to 15.
Bruno Soares
Former Australian Open doubles champion on BBC Radio 5 live sports extra
Cilic has to go big. He knows he has to play more aggressive than normal and trust in his weapons. He has the firepower to do that. He needs to look for the big forehand.
Gigi Salmon
Radio 5 live sports extra commentator at Melbourne Park
I've sat through a lot of ball bouncing by Cilic in the last year.
(He bounced it 18 times on his first serve, if you're interested...)
*Nadal 1-1 Cilic
Marin Cilic follows suit with a love hold.
If we continue like this, it could be a very long day/night.
Nadal 1-0 Cilic*
First point. Big serve. Return into the net from Cilic.
The Croat then smacks a forehand and backhand wide and then nets again.
A love hold gets the world number one off the mark.
Bruno Soares
Former Australian Open doubles champion on BBC Radio 5 live sports extra
Rafa, since I first saw him, his mental strength is incredible. He forgets things in one second. He just plays the next point. It's impressive.