Image source, Getty Images

Third seed Daniil Medvedev was pushed hard by Portugal's Nuno Borges but came through in four sets to reach the Australian Open quarter-finals.

Two-time finalist Medvedev failed to convert two match points at 5-4 in the third set before winning 6-3 7-6 (7-4) 5-7 6-1.

"He made me run [in the] third set," Medvedev said.

He will face ninth seed Hubert Hurkacz next after the Pole ended wildcard Arthur Cazaux's brilliant run.

France's Cazaux had beaten eighth seed Holger Rune in the second round but could not cause another upset as Hurkacz won 7-6 (8-6) 7-6 (7-3) 6-4.

Zverev sends the pressure back on to Norrie's shoulders with a hold to 15.

The 6ft 6in man is at the net and dominant, Norrie manages to defend a couple of times but can't do anything about the next one as Zverev volleys a winner.

David Law
Commentator on BBC Radio 5 Sports Extra

Norrie is playing so well and yet he very nearly got his service broken. There was a spell of five or 10 minutes where he lost his game. That could be a game changer.

Zverev is so good at getting through these epics but he probably gets himself into too many of them.

Image source, Reuters

Second seed Carlos Alcaraz found himself at 15-30 as he tried to serve out the first set. However, two aces help the Spaniard over the line and give him the lead over world number 60 Miomir Kecmanovic in this fourth-round match.

Alcaraz, 20, got the early break on Rod Laver Arena and didn't face a break point himself but the rallies got more entertaining as the set went on. Here's hoping that trend continues...

All credit to Cameron Norrie, he can't be doing much more here against the sixth seed.

Three times he has to save break points in that seventh game to nudge closer to the quarter-finals.

If he can get a break now, he would be serving for a place in the last eight.

A third break point comes for Zverev and a third break point goes for Zverev as he goes long. Back to deuce. Norrie hanging on.

Jonathan Jurejko
BBC Sport in Melbourne

What has been so impressive about Norrie today has been his bravery in the big moments.

He is staying committed to his approach and it has paid dividends in the important points.

Zverev punches away a volley at the net, but brilliant movement from both men around the court. Incredible stamina shown from both after nearly three and a half hours of action.

The crowd are loving this - and rightly so. Deuce.

Zverev misses a backhand and it's deuce - and signs of frustration shown from the German. Deuce. This would be a massive hold for Norrie if he can get it.

Norrie, two break points down, finds the line with a dream cross-court winner. That saves the first one, but there's still a break on the table, 30-40.

It's heating up nicely on Rod Laver Arena as both players hit their stride with strong hitting and clean winners which draw gasps from the crowd.

Second seed Carlos Alcaraz stays ahead of Serb Miomir Kecmanovic though and will serve for the first set of this fourth round match.

A loose forehand from the baseline sails wide from Norrie and Zverev has two break points, 15-40.

Worrying signs now for Norrie, 0-30 down on his serve. Zverev with a half chance here.

Norrie should send away a forehand winner with the court open, but he puts too much on it and it flies long.

But, if a shot was going to happen like that, when Zverev is in the middle of a routine hold to love isn't the worst time for it to happen.

Three-all final set.

Mark Woodforde
17-time Grand Slam doubles champion on BBC Radio 5 Sports Extra and BBC Sounds

I have a feeling this will see-saw back and forth, no-one is really creating a buffer. They’re matching each other.

A sweeping backhand from the baseline is placed perfectly and is timed superbly for Norrie, who was 15-30 down on his serve and facing some danger.

A fist pump follows another hold to 30. Still on serve. Getting tense.

A hold to love from Zverev and if there is some fatigue in the German's legs then a service game that lasts less than two minutes is just what he needed.

Mark Woodforde
17-time Grand Slam doubles champion on BBC Radio 5 Sports Extra and BBC Sounds

I am just wondering if Zverev is starting to fatigue, He wants to finish off points quickly.

If there is any fatigue in the legs he is going to feel it after those quick chases to the ball.

Norrie is in the lead for the first time overall since it was 5-4 in the opening set and on serve, before Zverev took three games in a row to grab the set.

How will the former world number two respond?