Some surly Tweeters threatened to emigrate as Ashleigh and Pudsey beat early favourites Jonathan and Charlotte and Only Boys Aloud - but Cowell and the rest of our nation of animal-lovers were cocked-leg-a-hoop.
The BBC must be sobbing as Simon Cowell once again drives away from ITV laughing - no doubt all the way to the ratings bank. Not to mention the Where Me Phone? single/ringtone/voting bank.
The threat from the much-vaunted The Voice was worrysome for a while as the BGT ratings slumped to an all-time low. But Twitter was awash with suspense throughout the final. Maddeningly, no one could call it as act after act raised their game.
This is showbiz, and Cowell has proved yet again he is the undisputed Talent Show King (unless it was all secretly his right-hand woman Shu Green, now poached by ITV).
And who'd have thunk it? Who else but Cowell could have had the vision to bring good old-fashioned British variety back to the mainstream - live, to boot! Just like the old music halls.
We even had Ant and Dec turning into Morecambe & Wise as they skipped on to the stage (though someone please tell them wearing matching ties should be compulsory).
All that's missing is Leonard Sachs' Good Old Days gavel. There's a thought for next time, and put all the judges in podiums. Maybe even with wigs on! David Walliams would love the chance to camp it up even more.
Making Walliams a judge was pure genius, and his We're Sailor Men turn with the showbears was a showstopper (as he wickedly wangled them into the final after all).
David's epic bromance with 'My Simon' blossomed so much he finally became the tail that wagged the top dog. Such fun to see old Mr Sour Face laughing and squirming. My God, there's a human being in there!
Variety is where Britain has real talent, and it's thrilling to see it back on TV with a bang, or even a buzz.
What I'd really love is for The Queen to have a buzzer at Buckingham Palace to sort the mutts from the pedigrees from the start! (I wonder if she's got the BGT app?)
Simon coming back also made the show. BGT and The X Factor just don't work as well without the put-downs that are as prickly as his hair.
In all the talent shows, the contestant corn could do with some hefty cutting - "This is the biggest moment of my life... I'm going to give it all I've got." Ugh.
While on BGT the judges should be banned from ever mentioning any "per cent" ever again, and I'd never vote for anyone who does the awful phone hand sign. Euw.
But the tension rocketed through the week of ruthless semi-finals. Seven acts being axed each night was Britain's Gone Brutal as only two out of nine went through. We watched in shock as the good went out with the bad and the ugly.
Losing zippy Mr Zip (Zipparah Tafari) and (temporarily) The Mend was bad. But brave little singer Malaki Paul breaking down in tears on stage after losing to dancers Nu Sxool on Wednesday was kid-crash TV.
It was made even worse when Ant and Dec made the poor lad turn round so the whole world could see his crumpled, bewildered devastation. Bad move.
With child acts they should bring the mums on stage to offer instant comfort to losers, then whisk them away to weep in the wings.
The judges also got it totally wrong with their baffling criticisms of Malaki - the most moving act of the night. I would have picked him every time!
But in the end a four-legged phenomenon won. And Simon SO deserved his doggie dream to come true.
"You know me, I love a dancing dog," he enthused when Ashleigh first appeared with Pudsey. "This is what I have been waiting for all... my... life!" he cheered as they were voted winners in their semi-final. And when they won he beamed: "My life's work is now complete!"
It was a fab Finale. Ashleigh wept, we wept and The Voice coaches must also be weeping into the big red revolving chairs that have stayed pointlessly static since the first round.
It was a one-tricky pony. They should have just crowned Ruth Brown straight off and gone home.
Mind you, Simon is still crying out for a knighthood. When Her Majesty sees Pudsey in the Royal Variety Performance the pooch might just win it for him.
Britain's Got Talent - doggie bones all round!