Parkside – also finalists in 2001 and 2008 – could only manage a 6-6 share of the points, but Summerside carried the day with a superior shot-margin aggregate of 118-95.
The format of three rinks at home and three rinks away saw Summerside sock it to the short-priced favourites, with wins for Martin Watt and David Poole that were supported by a great success for Mark Wilson at Parkside.
Watt lit up Summerside with a super-charged performance that saw him skip Neil Nisbet, Ross Nisbet and Jim Currie to a 35-9 triumph over Neil Watson.
Poole was immediately in the swim with a run of 2, 4, 2, 3, 4, 1 to skip Norrie Chalmers Alfie King and Kerr McKail into a 16-1 lead then onto a 22-13 win over Robert Donaldson.
Wilson added 2, 3, 2, 1 to stretch into a 17-5 lead, then traded well to skip Tony Drummond, Scott Walker and Tam Abercombie to a 26-12 win over Danny Jackson.
Parkside were kept in the fading picture by a 23-12 win for Derek Smith over Peter Miller away and success for Brian Salvona over Davy Hill (20-11) and Bob Ramsay over Mark Robertson (18-12).
“We do feel that Summerside is on the up and up and we achieved this fantastic result without ace skip Keith Taylor who was unavailable and will now be wondering if he will get his place back”, said spokesman Martin Watt.
Northern – finalists in 2009 – now have a higher Division 1 ranking than 2000 champions Leith, who are now in Division 2 and the current gulf in class showed with with a commanding 8-4 points victory.
Gordon Wilson Jnr and Ian MacDonald served up home wins for Northern and these were supported by away success for the rinks skipped by Mike Burns and Jamie Reid.
Willowbrae added to the prelim round shocks with a sensational shot margin win over three times Cup champions Tanfield while triumphs for lower ranking Tramways (Wardie), Goldenacre (Queensberry) and London Road Foundry (Dean) added to the romance of the Edinburgh Cup.