Salvatore Caruso caused an upset by beating Borna Coric to move into the quarter-finals of the Croatia Open Umag, while Federico Delbonis shocked Pablo Cuevas in Bastad.
Italian Caruso overcame the second seed 6-2 3-6 6-1 to seal his spot in the last eight.
The qualifier will take on Facundo Bagnis after breaking five times and fending off as many break points to see off Coric, who was among the leading contenders to take the title in his homeland.
Fourth seed Dusan Lajovic got the better of Andrey Rublev 6-4 6-3, while Bagnis knocked out Nino Serdarusic 6-3 6-3. Aljaz Bedene also advanced at the expense of Jannik Sinner.
Cuevas was sent packing in the round of 16 at the Swedish Open, going down 6-4 6-4 in a South American battle with Delbonis.
Frenchman Richard Gasquet was made to work for a 4-6 6-3 6-4 victory over Dennis Novak and Juan Ignacio Londero fought back to oust Hugo Dellien 4-6 7-5 6-3.
Joao Sousa also came from a set down to see off Swede Elias Ymer 4-6 6-4 6-2.
At Newport, rain halted Thursday's play, with Marcel Granollers taking the first set over Mischa Zverev 6-3 in the only singles quarter-final to get started at the Hall of Fame Tennis Championships.