Andy Murray guaranteed his place at the World Tour Finals on Thursday while Novak Djokovic and Roger Federer stayed neck and neck in their battle for world number one at the Paris Masters.
Djokovic overcame Frenchman Gael Monfils in the final match of the day with a 6-3, 7-6 (7/2) victory to become the eighth quarter-finalist.
The world number one now faces Murray in a repeat of their 2012 US Open final when the Scot won his first Grand Slam title.
Monfils lived up to his reputation as one of the most flamboyant players on the circuit with a combination of spectacular shots and pure power but Djokovic never wavered and closed out the match in 1hr 32 min.
"I managed to stay calm but I didn't serve well today," said Djokovic.
"The rest of my game was good and I knew I had to be patient but it's always difficult to play Gael in Paris with the home crowd and his powerful forehand."
Murray, 27, breezed to a 6-3, 6-3 third-round victory over Bulgarian Grigor Dimitrov to stay on course for a fourth tournament victory in just six weeks.
Murray joins Djokovic, Federer, Stan Wawrinka and Marin Cilic in reaching the season-ending showpiece in London with David Ferrer, Tomas Berdych and Kei Nishikori in possession of the other three spots but not yet assured places.
Canada's Milos Raonic is the only player who can gatecrash the top eight but needs to win the Paris tournament to guarantee his place.
Federer kept the pressure on Djokovic in the race for the year-ending number one spot with a gritty 6-4, 6-4 victory over French world number 176 Lucas Pouille.
A crucial break for the 17-time Grand Slam winner in the seventh game of the second set, the longest of the match, paved the way for victory over Pouille, who came through as a qualifier and had only recorded one Tour-level win before Paris this week.
It was Federer's 14th straight victory and sets up a quarter-final matchup against Raonic.
"It was a difficult match against an opponent who had nothing to lose but I played well even if he put me under pressure and I'm very satisfied," said Federer.
- Murray's 'bad year' -
Murray aimed a humourous retort at critics who have accused him of having had a poor season by writing "Bad Year!" on the courtside camera lens after his match.
"No, it wasn't a jibe, it's a bit of fun," Murray said.
"I mean, if people are going to ask me all the time why I've had such a poor year by my standards, then, yeah, you're allowed sometimes to say something in response to that.
"It's been a hard year, a tough year, but it hasn't been a bad year and it could have been a lot worse. Coming back from a surgery (on his back) is not easy at all."
Berdych is one win from also sealing his place in London after easing into the last eight with a comfortable win over Spaniard Feliciano Lopez.
Following a first-round defeat at the Valencia Open last week, the 29-year-old Czech evened his record against Lopez at six wins apiece with a 7-5, 6-3 victory.
Chasing an 11th ATP title, and third of the year, he now plays South African 14th seed Kevin Anderson for a place in the semi-finals.
Anderson won a three-hour thriller over Swiss third seed Wawrinka 6-7 (2/7), 7-5, 7-6 (7/3).
Former champion Ferrer stayed on track to reach a second straight Paris final as he swept aside Spanish compatriot Fernando Verdasco 6-1, 6-2.
He needs to reach the semi-finals to guarantee his spot in London and will now face Nishikori.
Nishikori is poised to become the first Japanese player to qualify for the World Finals after defeating French number one Jo-Wilfried Tsonga 6-1, 4-6, 6-4.
Raonic kept his slender London chances alive with a hard-fought 7-5, 7-6 (9/7) victory over Spaniard Roberto Bautista Agut.