British number two Cameron Norrie struggled to find his rhythm as he lost in straight sets to Monaco's Valentin Vacherot at the Paris Masters.
Norrie, 30, described his victory against world number one Carlos Alcaraz in the previous round as "the biggest win of my career" but was unable to reach that level again, losing 7-6 (7-4) 6-4.
Vacherot, who beat his cousin Arthur Rinderknech to win his first ATP title at the Shanghai Masters earlier this month, will face either Felix Auger-Aliassime or Daniel Altmaier in the quarter-finals.
"It was a really big performance," Vacherot said of his win over Norrie.