Janko Tipsarevic is the only seed through to the semi-finals of the AEGON International after he beat Grigor Dimitrov in straight sets on Friday.
Serbian Tipsarevic, seeded third for the grass-court tournament in Eastbourne, overcame Bulgarian Dimitrov 6-3 7-6 (7-2) in one hour and 28 minutes.
Ranked 34 places above world no.64 Dimitrov, Tipsarevic broke his opponent five times in the match and survived losing his serve on three occasions to progress at the Devonshire Park Lawn Tennis Club.
His reward is a semi-final against Japanese Kei Nishikori, who defeated Czech Radek Stepanek 6-2 6-3.
World no.59 Nishikori conceded 11 break-point opportunities to the man just two places above him in the rankings.
But 32-year-old Stepanek could only convert two of them, while losing his own serve five times.
In the other half of the draw, Italian Andreas Seppi won a hard-fought match against Olivier Rochus, battling past the Belgian 6-2 6-7 (5-7) 6-3.
World no.51 Seppi will take on Igor Kunitsyn in the last four after the Russian accounted for Frenchman Julien Benneteau with a comprehensive 6-2 6-3 victory.
Despite sitting just six places above Benneteau in the rankings, world no.71 Kunitsyn eased his way into the semi-finals, saving the only two break-points he faced to win in just one hour and 14 minutes.