This was the third defeat in as many matches for the Amateurs.
Paul Chimezie put Mqabba ahead on the 38th minute and Luca Casha doubled the score two minutes later.
Pietà and Qormi lead the way with 6 points, followed by Zabbar, Zejtun, Vittoriosa and Mqabba on 4, Sirens and Zebbug 3, Qrendi and San Gwann 2, Marsa, Rabat and Melita 0 and Pembroke -8.