Four-time champion Novak Djokovic has purred into the Australian Open fourth round with a commanding win over Uzbekistan’s Denis Istomin.

Djokovic, seeking his fourth straight Melbourne Park title, needed just under two hours to win 6-3 6-3 7-5 against the world No.49.

He will next meet Italian 15th seed Fabio Fognini, who before this year had won just one of seven Australian Open matches.

Fognini downed American Sam Querrey on Friday night to reach the fourth round for the first time.

By contrast, Djokovic, the Serbian second seed, stretched his Australian Open winning streak to 24 matches.

He produced some spectacular and athletic shot-making, but it came amid the freedom of rarely being placed under pressure.

Djokovic lost just three points on serve for the first set and needed just two break points to break Istomin’s serve twice.

The Serb managed just one break of serve in the second set, but that was always going to be enough as he was again unchallenged on his own serve.

The third set seemed headed the same way, after Djokovic gained an early break.

There was a momentary lapse, though, when the second seed was serving for the match.

At 30-30, he double-faulted, seemingly put off when a spectator called out as he was taking his second serve.

That gave Istomin his first break point of the match and he seized it to level the set at 5-5.

The reprieve was brief.

Djokovic broke Istomin’s serve again next game, pumped his fists and cried out in triumph, then quickly served out the match shiortly after midnight Friday.

Earlier, French ninth seed Richard Gasquet was upset by Spain’s 17th seed Tommy Robredo, whose four-set victory sets up a meeting with Switzerland’s Stanislas Wawrinka.