PARIS (AFP) - Novak Djokovic defeated Gilles Simon 6-3, 7-5 to record his 19th straight win and reach the quarter-finals of the Paris Masters on Thursday.
It was far from being the world No. 1's most commanding performance of late as he struggled with his serve, but it meant he has not dropped a set since the US Open final against Roger Federer in early September.
He has now won 26 sets in a row, taking him past his own previous best of 24 sets which he achieved in early 2014.
The Serb, who has won three of the four Grand Slam titles and five of the eight Masters 1000 series titles so far contested this year, dropped serve five times against the wily Frenchman, four coming in the second set.
But on each occasion he immediately struck back to prevent Simon from gathering any momentum.
The third round tie was at its best at the start of the second set, which opened with seven straight breaks of serve before Djokovic finally held to get the breathing space he needed.
Remarkably, he failed to serve out for the match at 5-4 up, but then ran off the next two games to extend his unbeaten run.
Djokovic will next play the winner of the tie between Jo-Wilfried Tsonga and Tomas Berdych for a place in the semi-finals of a tournament he has won three times previously, including the last two years.
The 10-time major tournament winner said his struggles on serve had been frustrating.
"I can assure you, losing four service games in a set, I don't think that has happened, you know, to me," he said.
"I'm not a serve specialist, but I think I have a solid serve and it hasn't happened for a long time.
"It wasn't pleasant, but I knew that I have a good return. I was feeling the ball very well from the back of the court.
"So that kind of was a positive to that, knowing that I can break him most of the time. That was the kind of mindset."
In earlier action, British second seed Andy Murray set up a quarter-final clash with Richard Gasquet of France by pounding Belgium's David Goffin 6-1, 6-0 in just 53 minutes.
The match had extra significance in that the two will lead their respective countries at the Davis Cup final in Ghent from November 27-29.
The Paris match was played on indoor hardcourt over best of three sets, while the Davis Cup final will be on clay over best of five, so both players agreed that it would be wrong to jump to too many conclusions.
But Murray certainly won some psychological points in what was just the second career meeting between the two men.
"It was good for me to get the chance to play him before the Davis Cup and see his game and the speed of his shots and where he maybe makes some mistakes from and things that he likes to do," Murray said.
"Obviously with the result, that's a positive. I mean, mentally for me it's a positive win." Gasquet's win over Kei Nishikori came when the Japanese star abandoned due to back pain while trailing 7-6 (7/3), 4-1.
The Frenchman, whose best showing in Paris Masters was a run into the semi-finals in 2007, said that Murray would present the toughest of challenges.
"He's one of the best players in the world. He's extremely difficult to beat every time because he makes few unforced errors," he said.
"He returns everything. He feels the game extremely well. He's one of the best competitors on the tour. He's really tough. He hits hard on both sides. He runs a lot. He has no weaknesses."
Playing later on Thursday was third seed Roger Federer up against giant American John Isner and Rafael Nadal in the last match up taking on Kevin Anderson of South Africa.