Novak Djokovic wins but fitness concerns remain at Australian Open

Novak Djokovic's game was back but question marks remain about his body after a straight-sets win over Albert Ramos-Vinolas in the third round of the Australian Open.

After his struggles in the heat against Gael Monfils, Djokovic looked much more assured in a 6-2 6-3 6-3 victory over his Spanish opponent. But Djokovic appeared to tweak something in his upper left leg or lower back at the end of the first set and twice needed treatment.

He said: "It was a straight sets win but almost two and a half hours, it wasn't that easy, I had to earn all of my points. I knew Albert is a great fighter.

"For me it's taking one match at a time. I had some incredible memories in Melbourne Park and that comes back every time I step out on the court but I have to be more humble with my expectations this time because I haven't played for six months, but I'm very happy with where my game is."

Having spent six months sidelined by an elbow problem, it is not surprising that Djokovic is experiencing a few physical niggles back in the heat of grand slam competition.

The problem did not affect him too badly, though, with Ramos-Vinolas unable to apply any real pressure as Djokovic moved through to a fourth-round clash with young Korean Chung Hyeon, who knocked out fourth seed Alexander Zverev in five sets.

Roger Federer continued his dominance over Richard Gasquet to march into the fourth round.

The defending champion went into the encounter with a 16-2 record against his French foe and having won the last eight matches, and there was never any real doubt that he would make it nine in a row.

There were flashes of brilliance from Gasquet, particularly on his famed single-handed backhand, but he could not get a hold on the Federer serve and the Swiss emerged a 6-2 7-5 6-4 winner.

Gasquet did not create his first break point until the 27th game of the match and, although he gave himself hope by getting back on serve, Federer swiftly crushed any thoughts of a comeback.

The second seed said: "I was able to maybe stay a little bit more on the offensive, protecting my serve a little bit better. The match was close and the end could have gone to a tie-break and then you never know. Richard played well and me too, I'm just happy to win tonight."

Only Federer, who next plays unseeded Hungarian Marton Fucsovics, and world number one Rafael Nadal have reached the fourth round without dropping a set.

Alexander Zverev suffered another grand slam letdown with a five-set defeat by fellow young gun Chung Hyeon.

The fourth seed is the highest-ranked player to fall so far in the men's draw but it was the manner of this loss that will be the most concerning for Zverev and his camp.

The 20-year-old German got into a row with the umpire about the light on Rod Laver Arena and won just five points in the final set to go down 5-7 7-6 (7/3) 2-6 6-3 6-0.

Zverev won five ATP Tour titles last season, including two at Masters level, and climbed to a high of third in the world, yet he has reached the fourth round at a slam only once and has not beaten a top-50 player over a best-of-five sets match.

Zverev has long been seen as the leader of the new generation and chose not to play at November's inaugural Next Gen Finals because he had qualified for the elite ATP Finals the following week.

In his absence, it was Chung who triumphed and the 21-year-old Korean celebrated reaching the last 16 at a slam for the first time, where he will face either Novak Djokovic or Albert Ramos-Vinolas.

Fifth seed Dominic Thiem had a much easier afternoon after his recovery from two sets down to beat Denis Kudla in round two, seeing off France's Adrian Mannarino 6-4 6-2 7-5.

The Austrian next meets the aptly named Tennys Sandgren, who had never won a grand slam match before arriving in Australia and won the battle of the unseeded players 5-7 6-3 7-5 7-6 (7/5) against Maximilian Marterer.

Another first timer through to the last 16 is Hungary's Marton Fucsovics, a former top junior who has struggled to translate that into the senior game. He defeated Nicolas Kicker of Argentina 6-3 6-3 6-2.

Julien Benneteau's final Australian Open before retirement came to an end with a 3-6 6-2 6-1 4-6 6-3 defeat by 25th seed Fabio Fognini.

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