Novak Djokovic made sure he will remain world number one at the end of this week after his stranglehold over Gael Monfils continued at the Madrid Open.

Djokovic, contesting just his fourth tournament of the season following a challenging time off-court, extended his perfect record against the Frenchman to 18 wins from as many matches.

He guaranteed a record-extending 369th week atop the ATP rankings with a 6-3 6-2 victory and will face Britain’s Andy Murray in the third round.

“I would probably rate it as the best performance of the year, I would say,” Djokovic said. “(It was a) very, very good performance.

“I’m very pleased, considering that up to now I was not playing my best tennis in the few tournaments that I played this year and still kind of finding my rhythm, finding my groove.”

Murray overcame Denis Shapovalov 6-1 3-6 6-2 in just over two hours and Djokovic welcomed the three-time grand slam champion’s return to fitness and form after a long-term hip injury.

“I have seen a few of his matches,” Djokovic told the ATP website. “He’s moving well, playing better and better.

“It’s really fantastic to see, because he’s an important player for our game. He’s made his mark in the history of our sport by winning multiple slams and gold medals and (being ranked) number one in the world. He’s one of the most important names that we have.

“To have him still compete is great, and to have him even play at the high level as the time goes by is impressive, considering the surgery and what he has been through in the last few years. His resilience and fighting spirit is really inspiring.”

Andrey Rublev, who defeated Djokovic in the final of the Serbia Open last weekend, was given a scare before seeing off British opponent Jack Draper in three sets.

Draper overpowered his Russian opponent in the opening set and led 3-0 in the third but Rublev fought back to claim a 2-6 6-4 7-5 victory.

The Londoner said: “I’m gutted obviously that I couldn’t sustain my level and come through the match but, at the same time, this week’s a new experience for me, being on the clay in a top event like this and playing a top-10 player.

“A good experience for me. Obviously I want to do well and win, but I’ve got to take the positives from that. I still feel like there is such a long way to go in all areas for me, which is really exciting.”