Britain's Liam Broady knocked out fourth seed and world number 31 Adrian Mannarino to reach the quarter-finals of the St Petersburg Open in Russia.
The 23-year-old beat the Frenchman 2-6 6-4 6-0 in one hour and 39 minutes.
Broady, ranked 242, had already gone through two rounds of qualifying before beating Latvian Ernests Gulbis in round one, his first ever win in the main draw of an ATP World Tour event.
He will now face Bosnia's world number 55 Damir Dzumhur in the last eight.