The second-seeded Stefanos Tsitsipas needed 2 hours, 22 minutes before he eventually prevailed against French player Gregoire Barrere 6-7 (6), 6-4, 7-6 (3).
The Russian top seed was joined in the last eight by Stefanos Tsitsipas, Felix Auger-Aliassime and Borna Coric but his compatriot Andrey Rublev, the sixth seed, was ousted by Taylor Fritz.