It was then left to Knox and he delivered in the final holes to set the mark at -14, which was equalled by Ryan Fox, but in the play-off the Scot proved himself with that repeat 40 foot putt.
Knox now heads to Scotland looking to win the Scottish Open.
He started the day six shots off the lead and completing the biggest comeback in Irish Open history presents some redemption for a player who finished second in this event in 2016.
"To make a putt like that, it's a dream come true", the 33-year-old told europeantour.com.
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The rescue got off to a good start, with the first boy coming out at 5.40pm local time (11.40am United Kingdom time). But Thai authorities had already began there rescue efforts before the vessel was completed without Mr Musk's help.
"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". "I feel bad for Ryan but I guess it was my time". "Fortunately I've done it before, so I knew I could do it".
"I hit the shots I wanted to down the stretch, felt comfortable out there and it was close". I had a great feeling on the greens.
"To make the Ryder Cup team, you have to win tournaments", Knox said.
After being joined on 13 under by Knox and Campillo, Fox had a glorious chance to moved two ahead again with a 12-foot eagle chance at the 17th but the putt slipped by to leave him one ahead.
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Hurricane Chris is expected to pass south of Nova Scotia on Thursday, creating high waves along the Atlantic coast. The National Weather Service issued a flash-flood watch for Puerto Rico, warning of thunderstorms and wind gusts.
Fox had to settle for $777,770 and one of three spots at Carnoustie, with the other two going to South African Zander Lombard and England's Andy Sullivan, who tied for sixth with Danny Willett and Thorbjorn Olesen on nine-under.
The victory earned Knox a prize of nearly £890,000 and his first win since the Travelers Championship in the USA in 2016 as he moves up to fifth place in the Race to Dubai standings.
Knox might have hoped the "apple throwing" incident would be overshadowed by his victory, but we reckon it's a part of the Irish Open that we shouldn't forget in a hurry.
Erik van Rooyen led by four overnight but fell away with a final-round 74. However, after taking just 27 putts on the final day, he's confident he's close to hitting his top form for The Open. I've done it before in the USA on the last hole, 12 feet.
Kylie Jenner Reveals The "One Thing" She Was Insecure About For Stormi
My stomach isn't the same, my waist isn't the same, my bu**'s bigger, my thighs (are) bigger. Just when a guy you like says that, I don't know, it just really affected me.