Scott Dalziel and Ryan Wallace both scored twice as East Fife inflicted a heavy 4-1 defeat on relegation-threatened Forfar, who slipped to just two points from the bottom of the Second Division table.
Dalziel put the visitors ahead with a clinical finish after latching on to Neil Janczyk's pass from the left in the 15th minute.
Janczyk was once again the provider three minutes later, his cross finding Wallace who headed into the top corner to double the Fifers lead.
Kevin Byers halved the deficit with a powerful strike after 32 minutes, but Wallace collected Darren Smith's pass eight minutes into the second half before firing past Forfar goalkeeper Greg Paterson to restore the away side's two-goal lead.
Substitute Craig Johnstone set up Dalziel to secure the win for John Robertson's team two minutes into injury time, condemning the hosts to their third defeat in four games.