Good morning, and welcome to our live coverage of Stefanos Tsitsipas against Roger Federer. The match begins at 8am UK time on the Rod Laver Arena.

TSITSIPAS 6-7 7-6 7-5 2-2 FEDERER: Federer is looking tired at times, and then suddenly brings out a serve to get himself to game point.

TSITSIPAS 6-7 7-6 7-5 2-1 FEDERER: Federer isn't looking happy on his forehand, and his passing shots are not hitting the mark.

TSITSIPAS 6-7 7-6 7-5 1-1 FEDERER: Late change of mind for Federer at the net, undecided whether to go down the line or across court. But Tsitsipas seems a little over-enthusiastic, putting a little too much on his returns.

TSITSIPAS 6-7 7-6 7-5 1-0 FEDERER: Three aces in a row for Tsitsipas, whose serve has been a bit all over the place today, if quick.

That was the 60th game these two have played. And it's the first time Tsitsipas has broken Federer.

TSITSIPAS 6-7 7-6 7-5 FEDERER: Two more break points for Tsitsipas - and this time they're set points. And he finally takes the first of them as Federer nets, and he has a two sets to one lead!

TSITSIPAS 6-7 7-6 6-5 FEDERER: So much pace on the ball from Tsitsipas. Another love hold.

TSITSIPAS 6-7 7-6 5-5 FEDERER: Federer tries to use delicacy of shot as he knows he won't overpower or outpace Tsitsipas now. A love hold.

TSITSIPAS 6-7 7-6 5-4 FEDERER: A quick clench of the fist as Tsitsipas does at least manage to hold again.

TSITSIPAS 6-7 7-6 4-4 FEDERER: Tsitsipas gets his first break points of the match. Two of them. But Federer's wile and guile is enough to hold his nerve - and his serve.

TSITSIPAS 6-7 7-6 4-3 FEDERER: Federer uses the drop shot to good effect to get his 11th and 12th break point of the day. He shanks a return, and Tsitsipas defends well to save the other.

To reiterate, we've been going for two and a half hours and nobody has broken serve yet.

TSITSIPAS 6-7 7-6 3-3 FEDERER: Kick serve from Federer to conclude another hold.

TSITSIPAS 6-7 7-6 3-2 FEDERER: Beautiful cross-court shot selection from Tsitsipas, again using his speed brilliantly.

TSITSIPAS 6-7 7-6 2-2 FEDERER: Federer holds, and Tsitsipas stares at the sky. He's definitely turning the screw on the Federer serve a touch more.

TSITSIPAS 6-7 7-6 2-1 FEDERER: Tsitsipas is using his height brilliantly, stretching well to reach the Federer returns.

TSITSIPAS 6-7 7-6 1-1 FEDERER: And it's a quick hold of serve for Federer to level up.