26-year-old Vacherot beat Serbian Laszlo Djere, world no. 17 Alexander Bublik, and 23rd-ranked Tomas Machac (retired) on his way to the round of 16 in Shanghai. The Monegasque never made it to the second round of an ATP 1000 Masters tournament before the Monte Carlo Masters in April, when he reached the second round.
27th seed Tallon Griekspoor was Vacherot's next hurdle in China. The Dutchman won his first match since July when he eliminated American Jenson Brooksby in round one, before winning by default when top seed Jannik Sinner retired due to the notorious Shanghai heat.
Griekspoor started on top with a break on love game in the very first game of the match, which gave him a lead he would not give away for the rest of the first set as the Dutchman dominated on serve with 20 won points from 23 service points.
Quick turnaround
Vacherot came to life in the second set, winning the first game on love before making Griekspoor work from behind as he took a 40-0 lead in the Dutchman's second service game. Griekspoor recovered, however, winning the last five consecutive points of the game.
After fending off six break points in the second-to-last game, Vacherot forced a tiebreak and dominated Griekspoor, beating him 7-1 to force a third and final set in Shanghai.
Vacherot turned up the heat in his service games this time, giving away just seven points from 28 serves. It paved the way for the Monegasque to upset Griekspoor in the ninth game, breaking Griekspoor on love and setting up a golden opportunity to book a unique quarter-final ticket.
The 26-year-old prevailed, leaving Griekspoor bitterly disappointed as Vacherot booked the first quarter-final ticket of his career at the ATP level. Vacherot next meets Holger Rune in Shanghai, who beat Giovanni Mpetshi Perricard after three sets on Tuesday.
Check out all the match statistics on Flashscore.
