Shabana beat Iskandar 3-2
Shabana made an ideal debut, winning two sets in a row (11-4, 11-8), but failed to maintain his pace as Iskander fought back to win two straight sets (12-10, 11-7) and level the score to 2-2.
The four-time world champion used his experience and eased past his rival 5-11 to win the decider and go through to the last 8.
Shabana, world number 3, will face Gregory Gaultier in the quarter-final on Wednesday.
Earlier in the day, Hisham Ashour, the younger brother of world number 1 Ramy, was beaten 3-0 by British champion Nick Matthew (11-8, 11-6, 13-1).
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