The city boys were one point clear in the country’s elite league before their match with The Gambia Armed Forces, who are scuffling for the league crown.
Real de Banjul scored three goals in the game to move four points clear on the first division league table.
The Gambia Armed Forces netted one goal in the match, which eventually proved to be a consolation for them.
Real de Banjul now clutched 21 points after 10 league matches.
The Gambia Armed Forces remained 10th place on the first division league table with 11 points after slipping to Real de Banjul 3-1.