Inverness-born Knox first grabbed the 14-under par clubhouse lead with a 72nd hole near 50-foot curling birdie putt and a round of 66 before being joined by big-hitting Kiwi Ryan Fox, who had posted a 68.
Knox then at the first extra play-off hole drained a similar 50-footer for birdie, and virtually from the same spot on the 18th, to claim the whopping £891,000 first prize cheque.
The win, Knox’s seventh success as a pro, will lift him some 44 spots to the new world No 43 and has seen Knox jump to fifth on the Race to Dubai.
It is the first time Knox has been in the world’s top-50 since August 2017 having dropped as low at 137th in May this year.
Knox has also leaped to 8th on the European Ryder Cup ‘World’ points table after being snubbed two years ago for Hazeltine ‘wildcard’ selection.
Knox’s success, only a second Irish win by a Scot since Colin Montgomerie won in 1991, also comes after he posted a stunning 65 a week ago to finish joint runner-up in the French Open.
And Knox heads to this week’s Aberdeen Standards Investments Scottish Open eager to win at Gullane ahead of teeing-up a week later at Carnoustie.
Victory also somewhat makes amends as he was second to Irish Open tournament host, Rory McIlroy, in the 2016 event at the K. Club.
And it was McIlroy who presented the gleaming Waterford crystal trophy to Knox after McIlroy failed to make any impression all week in not managing to break 70 and end T28th.
“The putts have been going in these last couple of weeks and I just had a great feeling on the greens and I wasn’t really aiming but just reacting to the line of the putt,” said Knox.
“I just kept going and going and this is unbelievable.”
Knox now has two weeks on home soil with not only the goal of a first Scottish Open triumph but matching Paul Lawrie’s feat of becoming the second Scot in three Carnoustie Open’s to lift the Claret Jug.
“I am thrilled to go back to Scotland for two weeks where I grew up,” he said.
“But right now, I’m going to enjoy this victory and this tournament. I’ll cross that bridge next week, but obviously over the moon right now, and can’t wait for everything.
“It was it was my time this week and I feel very lucky.
“My goal was to come to Europe for a month and then try and win a tournament, and to finish tied second last week in France and then to win this great tournament, I feel very lucky and unbelievable.”
Knox headed into the Ballyliffin final round at seven under par and a very distant seven shots behind South African Erik Van Rooyen who led the field by four shots.
However, the wheels were soon looking wobbly on ‘Von Rooyen’s Express’ and all-and-sundry, including Knox taking full advantage.
Knox grabbed a huge boost to his round when he landed his second shot at the uphill par-5 fourth hole to some six-feet right of the flag and found the bottom of the cup for an eagle 3.
It lifted Knox from a share of sixth into a then share of second.
Knox then birdied the sixth and after three straight pars but then after a birdie 3 at the 10th the Scot found himself in a four-way share of the lead on 12-under par.
And while he fell two off the lead he headed to the last sharing top-spot but only looked to have spoilt hopes of success in sending his final drive way right into rough and with 156-yards to the flag, having to jump up in the air to see the pin beforehand, he hit a blind shot to well left of the final flag.
Then in celebration to mirror his 2016 Travelers success, albeit not hurling his cap into the air, Knox clearly delighted in seeing a fifth birdie of his round disappear into the cup.
Fox’s consolation was a tee-time into The Open and with Nuneaton’s Andy Sullivan (69) and South African Zander Lombard (69) securing the other two Carnoustie places. Also sharing sixth was Danny Willett (72).