Tyrrell Hatton made two birdies in his first three holes to maintain his five-shot lead as he looks to become the first man to successfully defend the Alfred Dunhill Links Championship.
The Englishman made his European Tour breakthrough at this event last year as part of a stunning run of form that catapulted him to 14th in the Official World Golf Ranking.
He then made just two cuts in nine events from the Masters Tournament to the US PGA Championship but has back-to-back top tens since and carried that recent form into his defence.
Rounds of 68-65-65 over the first three days put him in a commanding position and he moved to 20 under on Sunday with Frenchman Grégory Bourdy his nearest challenger.
Ireland's Paul Dunne, England's Ross Fisher and Swede Joakim Lagergren were then at 12 under.
Bourdy quickly cut the lead to four with a birdie on the first but it was Hatton producing the fireworks as he found the Swilcan Burn with his second and chipped in to save par.
Lagergren has finished fourth in his previous two appearances at this event but quickly set about trying to improve that, starting with three birdies to move into outright third.
He soon had some company as Fisher birdied the second and third and Dunne also made a gain on the third for the fourth time this week over the three courses.
That trio were soon seven back, however, as Hatton birdied the second to re-establish his five-shot lead.
Another birdie on the third moved him further away from the pack and it was already looking like a two-horse race with Bourdy also making a gain.
Graeme McDowell picked up five birdies in 12 holes to sit at 11 under alongside Kiradech Aphibarnrat, Luke Donald and Victor Dubuisson.