Livi dropped to fourth after losing out to Falkirk on Tuesday night.
McNulty nearly grabbed the opener when he latched on to a Jason Talbot pass but he couldn’t find the net and strained his hamstring in the process.
He was replaced by Danny Mullen who made an impact quickly when Darren Dods felled him in the penalty area and Iain Russell swept the ball home.
Falkirk's Craig Sibbald hit the crossbar with a fine 25-yard volley, but Livi deservedly led at half-time.
But if Livi shaded the first half, the second 45 minutes belonged to the Bairns.
And they pulled level when Dods headed on a Thomas Grant corner to Higgins whose turning shot gave Andy McNeil no chance.
Mullen should have scored from a Russell cut-back but fluffed his lines.
And Falkirk got their noses in front when Grant’s free-kick hit off Talbot’s head and into the back of the net.
Russell was then sent off for a second booking.
And Falkirk clinched the win to leapfrog Livi into third.
McNeil, McCann, Booth (McDonald 77), Talbot, Garcia Tena, O'Brien, Ky.Jacobs, Fox, McNulty (Mullen 18), Morton (R.Gray 58), I.Russell
Subs not used: Donaldson, Jamieson
McGovern, Duffie, Kingsley, Dods, Flynn, Murdoch, Weatherston (Grant 39), McGrandles, Higgins, J Fulton, Sibbald
Subs not used: Vaulks, D Fulton, Leahy, Bowman
Referee: Brian Colvin
Official Attendance: 1100
Match report: Kieran Westbrook
Pictures: Steven Carrie