An injury-time own goal rescued a point for Raith Rovers, but the performance in Airdrie gave boss Barry Smith the chills.
Darren Young admitted the Fifers only had themselves to blame after they dropped two points at Bayview.
Despite a battling performance for 75 minutes, having played the match with 10 men, Forfar Athletic went down fighting in this foot-of-the-table clash.
Raith Rovers striker Greig Spence said confidence is returning after the 2-1 victory over Alloa on Saturday.
Arbroath manager Dick Campbell had no complaints after Stranraer condemned the Lichties to their fourth home defeat of the season at Gayfield on Saturday.
Inconsistency has been East Fife’s achilles heel this season, and proved so again at the weekend.
Raith Rovers forward Dario Zanatta hopes to make more of an impact from the start after a match-winning substitute’s appearance against Queen’s Park.
Dick Campbell admits his side didn’t reach peak form in the latest Angus derby, but the Arbroath boss was delighted Bobby Linn’s last-gasp winner delivered another three points to keep the Lichties snapping at the heels of Ayr United and Raith Rovers at the top of League One.
East Fife boss Darren Young sounded a warning to Saturday’s opponents Queen’s Park, saying his confident side can’t wait to turn on the style at Hampden.
Forfar Athletic’s revival under new manager Jim Weir continued with a 2-0 win over East Fife.