Andy Murray and Novak Djokovic continue to battle over the world number one ranking after both won in the third round of the Paris Masters.
Murray can overtake the 12-time Grand Slam champion if Djokovic fails to reach the final.
The Scot reached the last eight by winning a low-quality match with Lucas Pouille in straight sets, 6-3 6-0.
Serb Djokovic came from a set down against Bulgaria's Grigor Dimitrov before winning 4-6 6-2 6-3.
Djokovic will meet Croatia's Marin Cilic, the ninth seed, in the quarter-finals on Friday, before Murray faces seventh seed Tomas Berdych of the Czech Republic.
The Scot will not be on court before 18:30 GMT.
To become world number one for the first time, Murray must win the title if Djokovic fails to reach the final, although if the Serb should lose before the semis then Murray would only need to make the final.
Murray, though, reiterated that reaching the summit of the rankings is not a priority for the end of 2016.
"I can't control that," he told BBC Sport. "If Novak reaches the final, he keeps that spot. I just want to finish the year as best as I can.
"The goal wasn't to get to number one this year, but if it happens that's great. I've got a few months at the start of next year, February and March, where I didn't play very well at the beginning of this year and so can pick up points.
"That's the time when I was looking at as potential to do it, so I'm not stressing about it now."
Murray makes short work of Pouille
Murray needed two hours and 29 minutes to get past Fernando Verdasco in the second round on Tuesday and at times looked fatigued against Pouille.
Still, the Frenchman put up little resistance, with Murray winning eight successive games after the world number 17 had broken the Briton's serve midway through the first set.
Even with Murray below his best, Pouille's regular errors ensured this was no great spectacle, with the second set little more than a procession.
The victory is Murray's 71st in 2016, equalling his previous best calendar year of 2015.
A more straightforward route to the number one spot for Murray appeared possible when Dimitrov took the opening set against a low-key Djokovic, but the four-time champion fought back impressively.
Despite needing a medical time-out after twisting his knee in the second set, Djokovic dominated the closing stages to win in two hours and 24 minutes.
Cilic takes seventh place in London
Cilic won a tense encounter with Belgian David Goffin to qualify for the ATP World Tour Finals, which get under way in London on 14 November.
Cilic, 28, needed six match points before finally seeing off Goffin 6-3 7-6 (11-9) to reach the last eight in Paris.
The 2014 US Open champion joins Djokovic, Murray, Stan Wawrinka, Milos Raonic, Kei Nishikori and Gael Monfils in the line-up for London.
Dominic Thiem, Berdych or Jo-Wilfried Tsonga will complete the field at the O2 Arena.
"It's definitely something special, so it's great for me that I achieved it, especially in this kind of way in these last few weeks," said Cilic.
"I earned it, and that's, for me, an even bigger plus."