Leading by two with two holes to play at a windy Royal Birkdale, Harrington surprised many by taking on the green with his second shot at the par-5 17th.
However, both Harrington and his caddie Ronan Flood knew the player's trusty 5-wood was the right club and they were proven correct in spectacular fashion.
An outrageous shot set up a short eagle putt that Harrington converted, giving him the luxury of a stress-free final hole as he won The Open for the second year in succession.
Watch the Official Film of The 137th Open, which featured a memorable challenge from veteran two-time Champion Greg Norman before Harrington ultimately prevailed.