Roger Federer has made a comfortable start to his quest for a 100th title, dispatching Fabio Fognini in straight sets to ease into the quarter-finals at the Paris Masters.

The 37-year-old Swiss had only made a late decision to compete in Bercy after winning his 99th title in his home town Basel on Sunday but, despite a touch of raggedness, was sharp enough on Thursday to outclass the Italian 6-4 6-3 in his opening match.

Federer’s procession came after Novak Djokovic celebrated his return to the summit of world tennis with an even easier stroll into the last eight after Damir Dzumhur had to retire injured in the second set of their third-round clash.

Federer’s return to Bercy for the first time in three years delighted his vast Parisian fan club.

The Swiss wasn’t at his regal best against the flamboyant Fognini but didn’t need to be, with his opponent having never taken a set off him in three previous encounters.

Federer will play either Kevin Anderson or Kei Nishikori in Friday’s final eight.

Djokovic, who knew on Wednesday he would be world No.1 next week after Rafael Nadal’s withdrawal from the tournament through injury, was leading 6-1 2-1 when Bosnian Dzhumur retired at 6-1 2-1 after succumbing to a back problem.

Djokovic extended his winning streak to 20 straight matches as he maintained the remarkable spell of form that helped him rise from No.22 in June to the top of the game again.

“Reflecting on what I’ve been through in the last year, it’s quite a phenomenal achievement. And, of course, I’m very, very happy and proud about it,” the Serb told reporters.

Seeking a record-equalling 33rd Masters and record-extending fifth Paris title, Djokovic will face a much tougher test in the last eight against Marin Cilic, who looked in strikingly good form when beating Grigor Dimitrov 7-6(5) 6-4.

Fourth seed Alexander Zverev also cruised into the last eight with a 6-4 6-2 win over Diego Schwartzman.

He will play Karen Khachanov after the 22-year-old bested John Isner 6-4 6-7 (9-11) 7-6 (10-8).

Isner’s US compatriot Jack Sock, who’s the defending Paris Masters champion, also advanced with a 6-0 6-4 triumph over Malek Jaziri.

Sock goes up against Dominic Thiem on Friday after the 2018 French Open finalist edged Borna Coric 6-7 (3-7) 6-2 7-5.