Dunfermline halted their recent slump but were unlucky not to take maximum points in a scrappy match.
The Pars' Stephen Glass had the ball in the net after some good play from Tam McManus, only for the assistant referee to raise the offside flag.
Dunfermline had the better of the play, with McManus putting in a lively shift up front.
But Saints also had their chances and striker Kenny Deuchar had two efforts disallowed by the linesman.
St Johnstone: Main, Irvine, Stanic, McInnes, McManus, Anderson, McLaren (Weatherston 52), Sheerin, Deuchar, Jackson (MacDonald 83), Quinn. Subs Not Used: Stewart, Lawrie, Cuthbert.
Booked: McManus, Irvine.
Dunfermline: Murdoch, Woods, Wilson, Glass, Bamba, Murphy, Ryan (McGlinchey 75), Simmons, Burchill, McManus (Crawford 37), Muirhead (Hamilton 84). Subs Not Used: Harris, Paterson.
Booked: Ryan, Murphy, Woods.
Ref: S MacDonald