Jason Puncheon's hat-trick helped Barnet see off London rivals Dagenham & Redbridge at Underhill, despite playing the entire second half with 10 men.
Puncheon put them ahead from the spot after he was fouled by Marlon Patterson but Ismail Yakubu saw red for a second booking in first-half stoppage time.
Adam Birchall fed Puncheon to double the Bees' lead just after the break.
He completed his hat-trick with an left-foot drive, before Shane Huke grabbed a late Daggers consolation.
Barnet: Harrison, Porter, Devera, Yakubu, Gillet, Puncheon, Bishop, Leary (Carew 79), Nicolau, Hatch (Grazioli 85), Birchall.
Subs Not Used: Beckwith, Thomas, Tabiri.
Sent Off: Yakubu (45).
Booked: Yakubu, Leary.
Goals: Puncheon 41 pen, 50, 78.
Dag & Red: Roberts, Uddin, Okuonghae (Strevens 74), Boardman, Patterson (Green 57), Saunders (Foster 58), Huke, Southam, Sloma, Nurse, Benson.
Subs Not Used: Thompson, Taylor.
Goals: Huke 88.
Ref: Paul Taylor (Hertfordshire).