Novak Djokovic, fighting to extend his run as world number one, recovered from an early wobble to defeat Grigor Dimitrov in the last 16 of the Paris Masters yesterday.
The record four-time champion will remain above the in-form Andy Murray at the top of the rankings if he reaches the final in the French capital, but Djokovic was made to sweat before claiming a 4-6, 6-2, 6-3 victory.
He fell behind after losing serve twice in succession in an hour-long first set and then required medical treatment on his right knee after landing awkwardly while stretching for a return.
But Djokovic kept his calm as the errors mounted from Dimitrov to claim the second set with relative ease, and he broke early in the decider to wrest away control of the match.
The top seed next takes on Marin Cilic, who earlier punched his ticket to the Tour finals in London with a 6-3, 7-6 (9) defeat of David Goffin.
Murray faces French 13th seed Lucas Pouille later as the Briton continues his assault on Djokovic’s number one ranking.
The three-time major champion can supplant his long-time rival at the summit by lifting a maiden Paris title should Djokovic fail to reach the final.
However, if Cilic beats Djokovic in the quarter-finals today then Murray making it to Sunday’s final would be enough to propel the Scot to the top of the pile.
Cilic claimed the penultimate spot in the eight-man field for the prestigious November 13-20 event in London after seeing off Goffin on his sixth match point.
“That was the goal of the season for me, to reach the Tour finals in London,” said Cilic, who eliminated Goffin from contention in the process.
Fourth seed Milos Raonic shook off a slow start against Uruguay’s Pablo Cuevas to advance 4-6, 6-1, 6-2 and set up a quarter-final showdown with Kei Nishikori or 2008 champion Jo-Wilfried Tsonga.
American Jack Sock matched last month’s run to the last eight in Shanghai as he dumped out home hope Richard Gasquet 6-2, 3-6, 7-5.
He will meet compatriot John Isner in the next round after the latter halted the run of German qualifier Jan-Lennard Struff, winning 6-4, 6-7 (4), 6-3.
Late on Wednesday, Murray laboured past a determined Fernando Verdasco to reach the last 16.
The Briton was pushed to the limit by Verdasco in the French capital before prevailing 6-3, 6-7 (5), 7-5.
“It wasn’t the best match from my side. I got through it. I will play better tomorrow,” said Murray after sealing his 70th win of the season.
“I didn’t get any time on that court, because matches are from 11:00 in the morning and guys have warmup. So I have hit for like 45 minutes on the court beforehand, and it’s very different to last week, very different conditions.”
Murray, was scheduled to face Lucas Pouille for a place in the quarter-finals later yesterday.
Third seed Stan Wawrinka, the US Open champion, squandered a match point in the second set tiebreak to lose 3-6, 7-6 (6), 7-6 (1) to Struff.