Top seed Lucas Pouille resisted the strong challenge of Jiri Vesely to reach the quarter-finals of the Hungarian Open on Thursday.
Pouille was beaten by Albert Ramos-Vinolas at the semi-final stage of the Monte-Carlo Masters last week, but booked a last-eight showdown with Martin Klizan after a 6-3 4-6 7-6 (7-4) triumph in Budapest.
Slovakian qualifier Klizan defeated Bjorn Fratangelo, conqueror of Gilles Simon in the first round, 6-3 6-2.
Andrey Kuznetsov will face Paolo Lorenzi in the last eight after the Russian defied the odds to beat third seed Fabio Fognini 6-3 3-6 7-6 (7-4).
World number 87 Kuznetsov battled back from 3-1 down in the final set against the Italian, ranked 58 places higher than him, to force a tie-break, which he won courtesy of three mini-breaks.
Sixth seed Lorenzi needed three sets to get the better of Sergiy Stakhovsky, who was defeated 6-4 3-6 6-3.