Rafael Nadal gave a positive update on his fitness after defeating Britain’s Cameron Norrie to reach the fourth round of the Australian Open.

The second seed came into the tournament carrying a back problem that affected his service motion but revealed on Saturday that it is finally starting to feel better.

That is certainly timely news given his draw looks set to get much harder from here, with flamboyant Italian Fabio Fognini next up on Monday.

After beating Norrie 7-5 6-2 7-5, Nadal said: “Today it is better. It’s the first day I feel an improvement.

“I need to come back to my normal serving. Today is the first day that I started to serve again my normal serve. It has been an important victory for me. The biggest victory is the back is better.”

The main injury concern now surrounds Novak Djokovic, who suspected he tore a stomach muscle during his five-set victory over Taylor Fritz on Friday.

As expected, the world number one did not practise on Saturday and it is now a waiting game to see whether he is able to take to the court against Milos Raonic on Sunday.

Nadal was surprised to see Djokovic recover so well in the deciding set, saying: “I don’t know what’s he’s feeling because for two sets it looks like he’s going to retire and then in the fifth I think he played quite normal, a lot of points.

“A strange feeling for me as a spectator. But that’s it. He found a way to win, so well done.”

Fognini has beaten Nadal in four of their 16 meetings, including from two sets down at the US Open in 2015.

He was an impressive 6-4 6-3 6-4 winner over final Australian hope Alex De Minaur.

Daniil Medvedev won the first five-set match of his career despite a mid-match bust-up that led to his coach walking out.

Medvedev is known as a volatile character and this is not the first time that Gilles Cervara has seen enough, with the Russian frequently screaming towards his box after losing a two-set lead against Filip Krajinovic.

But the good news for both was that fourth seed Medvedev, one of the big favourites for the trophy, recovered to win 6-3 6-3 4-6 3-6 6-0 and reach the fourth round.

Medvedev felt it was the right decision, saying: “I don’t know what was going through his head, but at least what he said is that he was sure I’m going to win, and he just wanted to leave me alone to be calm.

“Sometimes maybe I will disagree but this time for sure it was a good thing to do.

“It happens once per year, two times per year maximum, maybe once in two years, but today it helped, and definitely we’re going to talk about it a little bit, but there is not a big deal.”

Medvedev won the biggest title of his career at the ATP Finals in November and this victory extended his winning run to 17 matches.

The Russian will next face American Mackenzie McDonald, who is through to the last 16 at a slam for the first time.

Medvedev said of his temperament: “Even three, four years ago, I could go crazy any match.

“Now I think I have made big steps already working on my mental strengths. Sometimes I’m a very temperamental person on the court so sometimes it can still get out, and usually it doesn’t help me to play good.

“I think he felt also the momentum change, so he started playing better. I’m happy that I managed to keep my cool in the fifth set.”

Medvedev’s compatriot, seventh seed Andrey Rublev, is another highly-fancied player and he continued his smooth progress through the draw with a 7-5 6-2 6-3 victory over veteran Feliciano Lopez.

After his five-set epic against Thanasi Kokkinakis in round two, fifth seed Stefanos Tsitsipas had a much easier time of it against Swede Mikael Ymer, winning 6-4 6-1 6-1.

Ninth seed Matteo Berrettini has had a strong start to the year and he got the better of three tie-breaks against Karen Khachanov.

Meanwhile, concerns were raised after a Greek tennis player who competed in the ATP Cup last week tested positive for coronavirus after arriving in South Africa for his next tournament.

Michail Pervolarakis tested negative prior to leaving Melbourne and wrote on Instagram that he believed he had caught the virus during his journey.