Keith Bonello scored the all-important goal on 22 minutes.
Meanwhile in the second match, Vittoriosa Stars defeated Mqabba 2-1 to move on top.
Joseph Okonkwo put Mqabba ahead on 12 minute but Mark Barbara turned out to be the hero for the Stars with two goals on the 82nd and 92nd minutes.
Vittoriosa lead the way with 27 points, followed by Lija and Pietà on 26 points, Naxxar and Marsaxlokk on 25, 24, Gudja 22, St. Andrews 21, Zejtun 17, Gzira 15, Birzebbuga 9, Dingli 8 and Mqabba 4.