After Knox made birdie on No. 18 to set the clubhouse target at 14-under par, Ryan Fox of New Zealand missed an 8-foot (2.4 metres) birdie putt that would have won him the Rolex Series event. I'm so happy. I said to my caddie (on the play-off hole) we've already made this putt, it can't be too hard.
Knox, who was on the 18th at the same time, hit a huge putt to put the pressure on the Kiwi. He had played the hole immaculately but saw a 12ft putt for a matching birdie horseshoe cruelly out.
"It's tough to describe how wonderful this feels". I remember thinking as soon as I hit it, I was like, 'Oh, I've hit it a bit firm, ' and it just started tracking and it dropped, unbelievable. When those putts go in, it's why you play golf.
"All the practice days, all the misses, all the bad moments are taken care of with putts like that". It's the best feeling in the world, to be honest.
Yet to win on the European Tour the 31-year-old said in the aftermath of his closest call yet that he was pleased with everything but the eventual result.
Knox was controversially overlooked for a Ryder Cup wild card in 2016 despite being ranked 20th in the world at the time, higher than seven members of the European team who would go on to lose at Hazeltine.
He made no secret of his bitter disappointment, and it appeared to linger during a desperate 18 months that saw him fall all the way to 137th place after the Memorial Tournament in OH in May. The leading four players not already exempt from the top-12 finishers qualified.
"I feel like I've made some improvements over the last couple of days on that and at least I know I'm trending in the right direction heading into the Open Championship".
Knox put his second shot to a position nearly identical to the one he found on the 72nd hole and rolled it home again, with Fox missing his own birdie attempt from 12 feet.
He secured his Open Championship berth by sharing second at last week's French Open and now heads home for next week's Scottish Open at Gullane before teeing up at Carnoustie.
Knox's fourth professional win hauls him back into the world's top 50 and gives Europe captain Thomas Bjorn plenty to consider.