Jordan Spieth (23), shot a final round of 69 to finish on 12 under par, with Kuchar second at nine-under. He is the first man to post four rounds in the 60s in an Open at Birkdale.
JORDAN SPIETH! After bogeying 3 of the first holes, Spieth caps an incredible back 9 with birdie-eagle-birdie-birdie to win the British Open pic.twitter.com/QL9emt6pB7— PGA Tour News (@GolfNews_PGA) July 23, 2017
Spieth had been top of the leaderboard after each of the first three rounds and his victory saw him emulate the great Jack Nicklaus in getting his hands on a third different major before turning 24.
3 shot lead
He had started the day three shots ahead of Kuchar but he very nearly threw it away, bogeying three of the first four holes as he went out in 37, three-over.
Spieth and Kuchar were level at eight-under standing on the 13th tee, when the former's wild tee shot forced him to take a drop and play his approach to the green from an adjacent practice ground.
He escaped with a bogey to trail by just one shot going onto the 14th, before recovering his nerve to pick up three birdies and an eagle in his next four holes to secure the Claret Jug in astonishing fashion.
Kuchar had four birdies but also three bogeys, including at the 18th, as he finished with a one-under 69 and missed out on what would have been a first major of his career at the age of 39.
Chinese golfer Haotong third
China's Li Haotong came from nowhere to finish third on six-under after a stunning seven-under-par last round of 63.
Rory McIlroy, the 2014 champion, finished with a 67 to share fourth on five-under with Spain's Rafael Cabrera-Bello.