Britain's Liam Broady and Arthur Fery were both beaten in their last-16 ties at the Nottingham Open.
Broady lost 7-6 (7-4) 6-4 to Japan's Sho Shimabukuro, before Fery was beaten 6-4 6-2 by fifth seed Dominik Koepfer.
A minute's silence was held on Centre Court after three people were killed and another three injured in attacks in Nottingham earlier this week.
Two 19-year-old students and a man in his 50s were stabbed to death in the city centre on Tuesday morning.
Shimabukuro, 177th in the world, 26 places below Broady, got the first break in the fifth game, although Broady broke back in the 10th game, but then lost the tie-break.