Airdrie bagged their first League One win in six games as they took Montrose apart at New Broomfield.
Lewis Jamieson's hat-trick was added to by a Craig Watson header, and the Diamonds had further chances to add to that lead, as Airdrie moved up to sixth in the table.
The Diamonds sparkled in the first half and were 3-0 up by the interval thanks to a brilliant double by Jamieson and a well crafted goal for Watson.
