Two goals from Paul Millar helped Elgin to an emphatic win and saw them leapfrog play-off rivals Berwick into fifth place.
Millar's close-range strike gave Elgin the lead after 35 minutes and that was doubled moments later when Archibald MacPhee found the top corner from distance.
The home side made it 3-0 early in the second half through Stuart Leslie, before Millar scored his second, converting Leslie's cross with a neat header.
Berwick's day got worse when Kevin McDonald was given a straight red card for a poor challenge on MacPhee on the hour mark.
Elgin peppered their opponents' goal for the remaining half hour but resilient goalkeeping from Jamie Barclay prevented further goals.