Max Purcell and Chris O'Connell have both been knocked out of the Sofia Open men's singles despite battling two-hour-plus performances in the Bulgarian showpiece.
O'Connell took a first-set lead against seventh-seeded Austrian Sebastian Ofner, ranked 22 places above the Australian world No.66. But Ofner came back to take the match 6-7 (5-7) 6-4 6-2 in two hours, 15 minutes.
Purcell, who had been seeded sixth, suffered a disappointing loss to Turkish wildcard Cem Ilkel. Ranked 259th in the world, more than 200 places below 45-ranked Purcell, Ilkel won 6-3 4-6 6-4.
Purcell did, however, progress in the doubles, partnering John-Patrick Smith to a 4-6 6-110-4 super tie-break win over Andrew Harris and Rinky Hijikata in an all-Australian affair. Purcell had earlier beaten Hijikata in the singles.
In the singles quarter-finals Ilkel now meets Briton Jack Draper who upset Italian No.1 seed Lorenzo Musetti 7-5 6-2 while Ofner plays French No.2 seed Adrian Mannarino who put out Albert Ramos-Vinolas 6-4 6-4.
In the other last eight pairings Jan-Lennard Struff faces Fabian Morzsan and Marton Fuscovics meets the winner of Pavel Kotov's match with Sebastian Baez.