Local boy Jon Voigt came off the bench to score the winning goal for Arbroath while East Fife slumped to their seventh consecutive league defeat.
Voigt, who joined his home town club from Forfar in January, was making only his second appearance and he had been on the field for just 17 minutes when the chance came his way.
Gavin Swankie played a free-kick out wide to Robbie Raeside, who hooked the ball into the danger area for Voigt to pounce and volley home from 10 yards.
"It's great to get off the mark," he said. "I just want to continue scoring goals for the club and hopefully that will help get us closer to the play-offs."
Arbroath went ahead in the 13th minute when a Jay Stein cross from the left found Stephen Rennie unmarked 15 yards from goal. The tall defender had plenty of time to choose his spot before shooting low past John Dodds.
The Fifers came close to equalising two minutes later, but John Bradford side-footed Stephen Fortune's cross past the post.
Swankie almost put the home side further ahead with a powerful shot which Dodds tipped over the bar.
The visitors pulled level three minutes before the interval when slack defending allowed Paul Hampshire to run in unchallenged before firing home from 16 yards.
East Fife could have edged ahead in the 56th minute, but Mark Peat saved Craig Smart's effort. Peat then saved from Kevin Gordon before Smart shot into the side netting after being put through by substitute John Martin.
Voigt's goal knocked the stuffing out of the Fifers, although Martin came close in the final minute with a shot which was deflected over the bar.