Martin Johnston, the summer signing from Highland League club Cove Rangers, was once again the home side's hero as he netted a first-half hat-trick to become the first Elgin player to top 20 goals in a season since they joined the SFL from Scotland's top non-league back at the turn of the millennium.
He took only three minutes to get his name on the scoresheet, meeting a cross from Chris Gardiner and lifting it over the keeper, before nodding it into the back of the net from a yard out.
Arbroath suffered a double blow before the 10-minute mark when a corner was met by Paul Kaczan. Steven Cook rashly handled the ball on the goal line, resulting in a red card and a penalty kick. Johnston confidently stepped up to fire home from the spot.
The Red Lichties gave themselves a lifeline in the 21st minute when former Peterhead man Robbie Raeside put an end to a goalmouth scramble by finding the back of the net from two yards.
However, a minute before half-time Elgin netted a crucial third. A Fraser Bremner cross was met by Johnston, who headed the ball against the bar before following in to net at the second attempt.
The home team sealed the win early in the second half when an Adam Nelson delivery was helped into the corner of the net by Kaczan to give City a three-goal cushion that they never looked like surrendering.