Victor Perez outlasted Matthew Southgate in a round-four thriller to claim his maiden European Tour title at the Alfred Dunhill Links Championship.
The duo were level heading into Sunday's play at St Andrews' old course and were still unable to be split by the 17th after a ding-dong battle.
However, a costly bogey from Southgate at the penultimate hole meant Frenchman Perez – who now resides in nearby Dundee – was able to lift the trophy thanks to a two-under-par 70 that left him at 22 under overall.
"The emotions were really high all day," said Perez, who graduated from the European Challenge Tour last season.
"It was really cold and windy, a long day out there and I felt I was able to battle.
"It wasn't easy, Matt played amazing. I was expecting some of the guys to charge and we were fortunate that it was kind of a one on one battle on the back nine.
"JP [Fitzgerald, Perez's caddie] knows the three courses like the back of his pocket, especially St Andrews, and it was a huge advantage for me to know where to hit it and really trust him."
A run of four birdies in five holes prior to the turn seemingly saw the momentum shift to Southgate, but dropped shots at 14 and 17 proved his undoing as he finished one stroke back.
Perez's victory means he enters the world's top 70, and also the top 20 in the European Tour's Race to Dubai Rankings.
Paul Waring and Joakim Lagergren finished two shots back in a tie for third, while Tommy Fleetwood and Tom Lewis each signed for sensational 64s to finish among a cluster of five players three strokes adrift.
Rory McIlroy has not quite been able to keep pace with the leaders this weekend but a classy 67 saw him finish the tournament at 15 under, one shot above Justin Rose.