Fifth-ranked Andrey Rublev and former world No 2 Alexander Zverev both crashed out of the Rotterdam ATP event on Wednesday.
Second seed Rublev went down 6-4, 6-4 to Australia’s Alex De Minaur who goes on to face American serve-and-volleyer Maxime Cressy for a quarterfinal place.
Rublev was the second seeded player to exit on Wednesday after Polish world No 10 and fifth seed Hubert Hurkacz lost to Bulgaria’s Grigor Dimitrov 7-6 (4), 7-6 (5) in the last 16.
Zverev, now ranked 17 in the world and attempting to rebuild his career after suffering ankle ligament damage at the French Open last year, slipped to a second round 4-6, 6-3, 6-4 defeat to Dutch player Tallon Griekspoor.
Jannik Sinner, fresh from lifting the Montpellier title last weekend, set-up an intriguing last-16 showdown with top seed Stefanos Tsitsipas by seeing off France’s Benjamin Bonzi 6-2, 3-6, 6-1.
Fourth seed Holger Rune knocked out French qualifier Constant Lestienne 6-4, 6-4.
“It was tricky. It’s a lot about finding the rhythm here in the beginning of the tournament and first match you have to really be on your toes,” said the young Dane.
Three-time major winner Stan Wawrinka made the last-eight by seeing off fellow former top 10 rival Richard Gasquet 6-3, 6-3.
The Swiss veteran won the tournament in 2015 and advanced to the final in 2019.