It was a marathon battle in which leads by the Dutchman were twice pegged back by the Cairo-born Canadian national champion who won the Houston Open in the USA last month. But, after 93 minutes – the longest match on the opening day – unseeded Anjema emerged triumphant in a 11-4, 6-11, 11-7, 4-11, 11-10 (2-0) scoreline.
Anjema's success – remarkably, the 23-year-old from The Hague's maiden first round win on the PSA Tour this year – takes him through to a quarter-final clash with Karim Darwish, the top-seeded Egyptian who cruised to an 11-5, 11-2, 11-8 win over Italian Davide Bianchetti in just 33 minutes.
The quickest victory of the day was recorded by Egypt's newly-crowned world junior champion Ramy Ashour, the fourth seed who beat fellow Egyptian junior international Mohd Ali Anwar Reda 11-4, 11-4, 11-3 in 25 minutes.
The teenager's next battle will be against England's sole representative in the $40,000 PSA Tour event's field Peter Barker - the No7 seed who dismissed Swedish qualifier Badr Abdel Aziz 11-6, 11-8, 11-3.
RESULTS: Rotary Heliopolis Squash Open, Cairo, Egypt
1st round:
[1] Karim Darwish (EGY) bt Davide Bianchetti (ITA) 11-5, 11-2, 11-8 (33m)
Laurens Jan Anjema (NED) bt [6] Shahier Razik (CAN) 11-4, 6-11, 11-7, 4-11, 11-10 (2-0) (93m)
[3] Mohammed Abbas (EGY) bt [Q] Yasser El Halaby (EGY) 11-6, 11-4, 11-8 (34m)
[8] Borja Golan (ESP) bt Renan Lavigne (FRA) 11-8, 11-8, 10-11 (0-2), 11-5 (62m)
[7] Peter Barker (ENG) bt [Q] Badr Abdel Aziz (SWE) 11-6, 11-8, 11-3 (37m)
[4] Ramy Ashour (EGY) bt Mohd Ali Anwar Reda (EGY) 11-4, 11-4, 11-3 (25m)
[5] Wael El Hindi (EGY) bt [Q] Tarek Momen (EGY) 11-4, 3-11, 11-7, 11-6 (35m)
[2] Olli Tuominen (FIN) bt [Q] Hisham Mohd Ashour (EGY) 11-6, 11-9, 9-11, 11-10 (2-0) (71m)