Greenock Morton defeated Inverness Caledonian Thistle 2-1 in Tuesday's cinch Championship fixture to move up to seventh place in the table.
Goals in each half from George Oakley and Jack Baird had Dougie Imrie's side in control before Adam Brooks netted a late consolation for the visitors.
The result means Arbroath - who host second-placed Raith Rovers on Wednesday - are now bottom of the table.
