Novak Djokovic and Roger Federer reached the Paris Masters quarter-finals on Thursday while Stanislas Wawrinka and Richard Gasquet claimed the final two places at next week's World Tour Finals.
Second seed Djokovic overcame American John Isner 6-7 (5/7), 6-1, 6-2 while Federer, the fifth seed, outclassed Philipp Kohlschreiber of Germany, 6-3, 6-4.
They were joined in the quarter-finals by Juan Martin Del Potro, Wawrinka and defending champion David Ferrer.
Swiss seventh seed Wawrinka beat Spain's Nicolas Almagro, 6-3, 6-2, and his place in the eight-man field at the World Tour Finals in London next week was later secured when Czech sixth seed Tomas Berdych defeated Milos Raonic, 7-6 (15/13), 6-4, to end the Canadian's chances.
Raonic's defeat also meant Gasquet was assured of the last available place in London even before the Frenchman had faced Japan's Kei Nishikori in his third-round match later on Thursday.
The eight players confirmed for London are Rafael Nadal, Djokovic, Ferrer, Del Potro, Berdych, Federer, Wawrinka and Gasquet.
Djokovic, who won in Paris in 2009 and is not only chasing a 40th ATP title but also the world number one spot, next meets Wawrinka, whom he defeated in epic five-set marathons at the Australian Open and US Open this year.
"It is a big challenge for me and Wawrinka," 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.
"He has been enjoying probably the best season in his career and he has one of the best one-handed backhands in the world."
Federer, the 17-time Grand Slam title winner, celebrated his place at the Finals in London with a 6-3, 6-4 victory over Kohlschreiber.
He now meets 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.
On Del Potro, against whom he lost in the Basel final last weekend, the 32-year-old Federer said: "It's an important match for both of us and also looking ahead to London where we could meet. It could give one of us an advantage for London so it's a key match.
"I like to play him, he's one of the best indoor players on the Tour."
World number one Nadal is in action in the final match of the day against last year's surprise finalist Jerzy Janowicz of Poland with the winner to face Gasquet or Nishikori in the last eight.
Ferrer, the third seed, showed little mercy against Frenchman Gilles Simon.
His 6-2, 6-3 win allowed him to stay in the hunt for a third ATP title this season following Auckland and Buenos Aires.
His title defence continues on Friday with a last-eight tie against sixth seed Berdych.