Ige Abdullahi Adeshina scored the all-important goal for Lija.
The Amateurs make their return to elite football after an absence of 48 years. Next Saturday, they will be facing leaders Rabat Ajax in a direct clash for the championship.
In another match, Zejtun Corinthians returned to victory, beating St. George’s 5-1.
Kenneth Abela notched a hat trick with Carmel Formosa and Kalin Ganchev scoring the other two goals. Leonardo Rocha Dos Santos scored the only goal for the Saints.