The Eastern Premier winners knew they had been in a game but, in truth, Ayr, the champions of the Western Union, gave themselves too much to do after a dreadful start saw them slump to 8-3.
Winning captain Kenny Reid declared: “It’s a fantastic feeling to be national champions after a great season.
“Winning the Eastern Premier was a brilliant effort because it’s a division that is full of quality sides and we had to show a lot of consistency.
“Now this win today tops everything off brilliantly and I think we were worthy winners in the end.
“It was a good toss to win and we took advantage of the conditions early on but Ayr came back at us well.
“They made a real game of it which is no surprise as all teams from the west fight all the way.”
Chasing 170 for victory, Aberdeenshire made a solid start though Chris Venske survived two confident lbw shouts from the lively Scott McElnea.
Venske took advantage with a beautifully struck six over long-off and also stroked four boundaries as he and Callum Howard put on 54 for the first wicket.
However, having made 30 Venske miscued a McElnea delivery and was well caught by Matthew McClymont as Ayr made the breakthrough.
‘Shire were already well ahead of the required rate and sensible accumulation was all they needed to secure the title but Ayr were clearly not going to go down without a fight.
Skipper Andi McElnea emphasised the point by removing Howard for 27 with his first delivery and was rewarded for another bowling change when he brought back his brother Scott who promptly had Hayes van der Berg well pouched by keeper Neil Smith.
Ayr had a further two successes but paid the price for giving Dons professional Harsha Cooray a life before he had scored.
The Sri Lankan took full advantage with a match-winning 54no, stroking just three boundaries but picking the gaps with great skill while Callum Martin gave solid support with 22no as the Mannofield side won with thirteen balls to spare.
Earlier Aberdeenshire initially made light of the absence of two main-line bowlers after putting Ayr in to bat in conditions which gave a huge advantage to the side which won the toss.
Skipper Tyler Buchan and fellow seamer Adrian Neill were both absent but youngster Rory Martin made the most of his opportunity as Ayr were reduced to 8-3 in the third over.
Martin removed Andi McElnea, caught behind by Kenny Reid with his first delivery and was celebrating again four balls later when West Indian professional Steve Liburd played on for a duck.
Hayes van der Berg weighed-in with the wicket of Shujaa Khan as Ayr were reduced to 8-3.
Reivers opener Smith hung around for a little longer before clipping a catch to Venske at mid-wicket as Martin claimed his third wicket.
Venske turned wicket-taker with two scalps in a single over as the procession continued and Ayr, on 37-6, were in danger of total capitulation.
However, Dougie Johnstone, their most experienced player, produced the sort of controlled innings his team desperately needed with a battling half-century.
Neil Logan offered spirited support as Ayr added 77 priceless runs for the seventh wicket.
Logan had stroked four boundaries before Martin returned to the attack and had him trapped in front for 29.
Scott McElnea’s arrival at the crease brought acceleration, the former Scotland U19 all-rounder striking the only six of the Ayr innings when he hoisted a Hamish Niven delivery over the rope at deep mid-wicket.
McElnea also clouted four boundaries on his way to a 21-ball 30 but his departure, caught by Callum Martin off Cooray, left Johnstone running out of partners.
A century would have been a fitting reward for such a splendid knock but, having reached 72 from 154 deliveries with ten boundaries, Johnstone became Cooray’s second victim thanks to a fine diving catch by Venske.
His departure signalled the end as the final wicket fell soon after with Ayr on 169 having failed to use up more than five of their overs but they had given an enthusiastic support something to cheer after such an inauspicious start.
Rory Martin was the pick of the attack with 4-39 while Venske claimed 3-14.