Rafael Nadal moved into the Paris Masters quarter-finals by beating Uruguay's world number 36 Pablo Cuevas.
Spaniard Nadal, 31, beat his 31-year-old opponent 6-3 6-7 (5-7) 6-3 and faces Serbian qualifier Filip Krajinovic, 25, in the last eight.
Nadal's second-round win over Hyeon Chung on Wednesday ensured he will end 2017 as world number one.
Earlier on Thursday, David Goffin became the first Belgian to qualify for the season-ending ATP Tour finals.
Lucas Pouille's defeat by American Jack Sock ensured Goffin took the penultimate spot for the November 12-19 tournament.
Nadal, Roger Federer, Alexander Zverev, Grigor Dimitrov, Dominic Thiem and Marin Cilic have also qualified for the eight-man event at The O2 in London.
The last spot is currently held by Spain's Pablo Carreno Busta, but Argentina's Juan Martin del Potro can beat him to it by reaching the semi-finals at the Palais Omnisports in Bercy.
Del Potro, 29, faces ninth seed John Isner in the last eight after the American beat Grigor Dimitrov 7-6 (12-10) 5-7 7-6 (7-3).
Last year's runner-up Isner can qualify for London by winning the tournament.
In the other quarter-finals, French wildcard Julien Benneteau will play Roberto Bautista Agut or Marin Cilic after beating Goffin.
Sock, the world number 22, plays Spaniard Fernando Verdasco, who beat Thiem 6-4 6-4.