In the two longest matches on the opening the day of the Case Swedish Open, Egyptians Karim Abdel Gawad and Tarek Momen produced notable upsets to reach the quarter-finals of the PSA World Tour International 70 event celebrating its tenth year at Linköping Sporthall in Linköping, Sweden.
Gawad, the 21-year-old world No26 (pictured) making his debut in the biggest event in continental Europe, recovered from a game down to beat experienced Dutchman Laurens Jan Anjema.
The Cairo newcomer squandered a match-ball in the fourth game when hoping for a stroke and given 'no let' - allowing Anjema, the 30-year-old world No14, to force the match into a fifth game decider.
But the young Egyptian's inventive play continued to have the edge over the powerful left-hander as Gawad went on to close out the match 6-11, 11-7, 11-9, 10-12, 11-5 after 88 minutes.
Momen went into the battle against fourth seed Daryl Selby with the psychological advantage of a win over the higher-ranked Englishman in their last meeting.
But Selby looked determined to make amends as he took the first game for the loss of just three points, then recovered from dropping the second on a tie-break to take the third and move 2/1 ahead.
However 24-year-old Momen - now an established figure in the world top 20 - reclaimed the advantage to win the next two games to record a 3-11, 12-10, 9-11, 11-8, 11-8 upset after 78 minutes.
The two unseeded Egyptians now face off for a place in the semi-finals.
Another upset looked on the cards when Nordic hope Henrik Mustonen, a qualifier from Finland, opened up a 2/1 lead against Australian number one Cameron Pilley. But the tall world No18 from New South Wales recovered the upper hand before taking the match 11-7, 10-12, 8-11, 11-7, 11-2 in 64 minutes.
Defending champion Gregory Gaultier also faced a tough opening challenge from Swiss number one Nicolas Mueller, the world No21. Frenchman Gaultier, ranked 17 places higher, needed 53 minutes to earn his victory, but did so in straight games, winning 11-9, 11-4, 11-6.
 Nick Matthew (ENG) bt [Q] Chris Simpson (ENG) 11-6, 11-5, 11-3 (36m)
Cameron Pilley (AUS) bt [Q] Henrik Mustonen (FIN) 11-7, 10-12, 8-11, 11-7, 11-2 (64m)
Karim Abdel Gawad (EGY) bt Laurens Jan Anjema (NED) 6-11, 11-7, 11-9, 10-12, 11-5 (88m)
Tarek Momen (EGY) bt  Daryl Selby (ENG) 3-11, 12-10, 9-11, 11-8, 11-8 (78m)
 Peter Barker (ENG) bt [Q] Adrian Waller (ENG) 11-5, 11-8, 11-9 (46m)
Simon Rosner (GER) bt Rasmus Hult (SWE) 11-7, 11-3, 11-3 (35m)
Tom Richards (ENG) bt [Q] Jonathan Kemp (ENG) 11-7, 11-7, 13-15, 11-7 (40m)
 Gregory Gaultier (FRA) bt Nicolas Mueller (SUI) 11-9, 11-4, 11-6 (53m)
 Nick Matthew (ENG) v Cameron Pilley (AUS)
Tarek Momen (EGY) v Karim Abdel Gawad (EGY)
 Peter Barker (ENG) v Simon Rosner (GER)
 Gregory Gaultier (FRA) v Tom Richards (ENG)