Peamount picked their eighth victory in nine SSE Airtricity WNL games after a 3-0 win over Bohemians on Saturday.
Stephanie Roche put them ahead on the stroke of half-time, before efforts from Tiegan Ruddy (penalty) and Karen Duggan saw them home in the second half.
It leaves the defending champions four points clear of Shelbourne, who aren't in action again until next weekend - both clubs have played 19 rounds of games.
Elsewhere, a Laura Shine hat-trick helped Cork to a 4-1 victory over DLR Waves.
⚽️ GOAL | @KarenDuggan91
— Women's National League (@LoiWomen) September 25, 2021
Peamount extend their lead from another set-piece as Duggan drills the ball into the back of the net@bfcdublin 0-3 @peamountutd
Watch LIVE 👉 https://t.co/YoFjlE4EzF#WNL | #LOITV pic.twitter.com/dr9KQOAFMM
