Dungannon's Ryan Mullan in action against Michael Carvill

Champions Linfield crashed to a fourth straight defeat as Dungannon pulled off a shock win in the first leg of the Co-Operative Insurance Cup.

Ryan Mullan put the Swifts into the lead in the second minute with a far post header from Rodney McAree's cross.

Two minutes before half-time Jamie Tomelty pounced on a William Murphy mistake to make it two and a Marc McCann shot added a late third.

Holders Linfield now face a massive task in the second leg on 12 November.

Linfield's bad run started when they were beaten 3-0 by Derry City in the Setanta Cup on 6 October.

They failed to score in their next two games as well, going down 2-0 at bottom club Ballymena, and then losing at home in the league for the first time in over two years when Lisburn Distillery won 2-0.