As if he’d never been away, Novak Djokovic looks to have returned to tennis like a man on a mission.

In first tournament since all the dramas of his isolation and deportation before the Australian Open, the Serb looked every inch the world No.1 again as he powered through just his second match in three months at the Dubai Tennis Championships.

Djokovic this time brushed off a formidable challenge from Karen Khachanov 6-3 7-6 (7-2) to reach the quarter-finals on Wednesday night under the lights at the Aviation Club.

And just as against the rising star Lorenzo Musetti in his comeback match on Monday, the Serb seemed wholly inspired by the apparent love from the big crowd as he played the sort of tennis only he can.

“I missed it, obviously. This is my life. This is what I have known to do – and will still keep on doing – for the last 20 years. Professional tennis is my love,” Djokovic told his admirers on court.

“I enjoying bringing positive energy and memories for people who watch.”

Djokovic knows he could also lose his precious number one ranking next week even if he should win in Dubai because Russian Daniil Medvedev will go to the top of the pile if he wins the current event in Acapulco.

Yet here was a performance from Djokovic which seemed to dare anyone to suggest there’s currently still a better player out there as he subdued world No.26 Khachanov, victor over Australia’s No.1 Alex de Minaur in the previous round.

Seeming to have no ring rust at all, he was imperious in the opening set and mentally as tough as ever when Khachanov recovered from an early break of serve to fight back and take the second to a tiebreak in a really high-quality duel.

Djokovic again raised his level when he needed against a tough opponent who’s given him plenty of trouble before, taking early control of the tiebreak and claiming victory on his first match point.

“I was feeling excited and motivated, but also at the same time I was feeling stressed,” admitted Djokovic, who’ll next face a quarter-final against Czech qualifier Jiri Vesely, who earned the shock of the day by defeating Doha champion Roberto Bautista Agut 6-2 6-4.

Earlier, Andy Murray was left having to wait for his landmark 700th career win after a 7-5 6-2 defeat by Italian youngster Jannik Sinner, who once again demonstrated why he’s going to be one of the sport’s big stars.

Andrey Rublev, fresh from his win in Marseille, beat South Korean Soonwoo Kwon 4-6 6-0 6-3 but Australia’s last hope disappeared with Alexei Popyrin’s 6-4 7-6 (9-7) defeat by Ricardas Berankis.