PARIS, France (AFP) — Novak Djokovic overcame American John Isner, while Roger Federer outclassed Philipp Kohlschreiber as they joined Juan Martin Del Potro, Stanislas Wawrinka and defending champ David Ferrer in the Paris Masters quarter-finals yesterday.

In the afternoon session, Federer celebrated his place at the World Tour Finals in London with a 6-3, 6-4 victory over Germany’s Phillip Kohlschreiber as the former world number one continues his return to form.

He now meets colossal Argentine Juan Martin Del Potro who defeated rising Bulgarian star Grigor Dimitrov 3-6, 6-3, 6-4 in a high-quality match on court one.

Djokovic, who won in Paris in 2009 and is not only chasing a 40th ATP title but also the world number one spot, dropped the first set before storming back for a 6-7 (5/7), 6-1, 6-2 victory over Isner.

He now meets Wawrinka against whom he has already played some classic matches this season, notably their five-set semi-final at the US Open where the Serb finally prevailed.

“It is a big challenge for me and both Wawrinka, also,” said Djokovic who also has the Davis Cup final to consider on November 15.

“It’s not the first time I’m playing against him at this stage of a tournament. It’s not best of five, so we will not go the fifth set,” he joked in reference to their US Open epic.

Wawrinka took another step towards booking his ticket for London when he comfortably defeated Spaniard Nicolas Almagro 6-3, 6-2.

Seventh-ranked Wawrinka will join his Olympic doubles partner Federer for the season’s grand finale in the English capital, should either Frenchman Richard Gasquet or Milos Raonic of Canada lose their third-round matches later on Thursday.

When asked prior to the Djokovic match who he might prefer in today’s quarter-finals, he admitted Djokovic was the man he wanted.

“If I do have a preference it would be Novak because we’ve had some great matches in the past.”

Ferrer showed little mercy against Frenchman Gilles Simon and by converting three of six break points, that was the difference as he stays in the hunt for a third ATP title this season following Auckland and Buenos Aires.

His defence continues today with a potential last eight tie against sixth seed Thomas Berdych or Raonic.

Gasquet takes on Japanese world number 18 Kei Nishikori for the right to play world number one Rafael Nadal or last year’s surprise finalist Jerzy Janowicz of Poland in the last four.

Canada’s Davis Cup semi-finalist and 10th seed Raonic must beat Czech world number six Thomas Berdych to keep his flickering London hopes alive.

The 22-year-old has to reach the final in Paris to snatch one of the final spots from Wawrinka or Gasquet, with these three players battling for the final two slots.