World number one Carlos Alcaraz swept aside Grigor Dimitrov 6-1 6-3 to book his place in the Paris Masters quarter-finals on Thursday and reigning champion Novak Djokovic advanced with a 6-4 6-1 win over Karen Khachanov.
Top seed Alcaraz dominated from the outset and dropped just two points on serve in the opening set before fending off a second-set fightback from Bulgarian Dimitrov to close out the match in one hour 12 minutes.
"(Grigor's) level is very much not the level you saw today, but I played very well," said Spaniard Alcaraz, who is chasing a third ATP Masters 1000 title this season.
"At the end of the second set it was tougher for me, he came back, he raised the level and obviously it was tough. He had the chance to go up in the second set, I had to stay calm in that moment and show my best to not allow him to go up."
Djokovic, a six-times winner at the ATP Masters 1000 event, delivered a commanding performance in his straight-sets victory over Russia's Khachanov, hitting 18 winners.
The Serbian will take on Lorenzo Musetti for a place in the semi-finals after the Italian youngster ousted Roland Garros finalist Casper Ruud.
Musetti, 20, fired 37 winners as he came from a set down to eliminate third-seeded Norwegian Ruud 4-6 6-4 6-4 and advance to his maiden ATP Masters 1000 quarter-final.
"He (Ruud) was playing really well and I had to play my best tennis to beat him. I am really happy that all the hard work I am doing keeps improving me. I am really proud of this win," said Musetti.
Danish teenager Holger Rune set up a quarter-final clash with Alcaraz after taking down seventh seed Andrey Rublev 6-4 7-5 and Canadian Felix Auger-Aliassime stayed on course for a fifth title of the year with a 6-1 6-3 demolition of French veteran Gilles Simon.
Russian Rublev and Auger-Aliassime secured their places at the season-ending ATP Finals in Turin on Wednesday.