Frenchman Julien Balbo and Kuwaiti Bader Al Hussaini claimed unexpected places in the quarter-finals of the Avrupa Konutlari International after dismissing seeds in the PSA World Tour Challenger 10 squash event in its second year at Avrupa Konutlari Ataken in the Turkish city of Istanbul.
According to the draw, Balbo's 11-3, 11-8, 11-9 defeat of second-seeded compatriot Yann Perrin was an upset - but it was actually the 32-year-old world No89's sixth successive Tour win over higher-ranked Perrin since January 2007.
Balbo continues his battle with fellow countrymen in the next round where he takes on Geoffrey Demont after the medical student from Aix-en-Provence despatched local hope Huseyin Gumus 11-4, 11-1, 11-3.
In the same half of the draw, Al Hussaini twice recovered from behind to overcome third seed Kashif Shuja, the world No90 from New Zealand, 7-11, 13-11, 8-11, 11-7, 11-9.
The 28-year-old from Kuwait, ranked 124 in the world, now faces France's unseeded Joan Lezaud who beat Dutch qualifier Frank Hartkoren 13-11, 11-5, 11-6.
But a Dutch qualifier did survive the first round when Bart Ravelli upset higher-ranked Frenchman Fabien Verseille 11-7, 9-11, 11-3, 11-6.
Ravelli, a 24-year-old from Hoofddorp, now lines up against top seed Jan Koukal. The Czech number one needed just three games to overcome Swiss qualifier Patrick Miescher 11-7, 11-6, 11-8.
RESULTS: PSA Challenger 10 Avrupa Konutlari International, Istanbul, Turkey
 Jan Koukal (CZE) bt [Q] Patrick Miescher (SUI) 11-7, 11-6, 11-8
[Q] Bart Ravelli (NED) bt Fabien Verseille (FRA) 11-7, 9-11, 11-3, 11-6
Raphael Kandra (GER) bt [Q] Osama Khaled Khalifa (EGY) 11-6, 11-7, 11-7
 Jens Schoor (GER) bt Alejandro Garbi Caro (ESP) 6-11, 5-11, 11-9, 11-9, 11-5
Bader Al Hussaini (KUW) bt  Kashif Shuja (NZL) 7-11, 13-11, 8-11, 11-7, 11-9
Joan Lezaud (FRA) bt [Q] Frank Hartkoren (NED) 13-11, 11-5, 11-6
Geoffrey Demont (FRA) bt Huseyin Gumus (TUR) 11-4, 11-1, 11-3
Julien Balbo (FRA) bt  Yann Perrin (FRA) 11-3, 11-8, 11-9
 Jan Koukal (CZE) v [Q] Bart Ravelli (NED)
 Jens Schoor (GER) v Raphael Kandra (GER)
Bader Al Hussaini (KUW) v Joan Lezaud (FRA)
Julien Balbo (FRA) v Geoffrey Demont (FRA)
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