كتب : Hatem Maher
The in-form Egyptian winger fired the visitors in front after 27 minutes.
He collected a pass from Lierse skipper Jurgen Cavens on the edge of the area before drilling a trademark left-footed shot that found its way into the net.
Abdul-Wahed's compatriot Ahmed Samir, who has also been in sparkling form this season, was left on the bench.
Fellow Egyptian midfielder Sherif Al-Beyali missed the game through injury.
A goalless draw for Lierse in the second leg will be enough to send them through to a final four-team playoff that will determine the team who will seal promotion to the top flight.