It was a triumphant return from injury for Macfie, who trains with the England squad. He finished on seven under to take the crown at his third and final attempt before leaving the junior ranks.
Macfie, 18, had to take six weeks out last season after injuring his left side, so his win is particularly sweet.
“My injury set me back and my confidence was a little bit low. But with my coach and my training (in the gym) I’ve got to a place where I’m injury free and swinging pain free and that’s made the difference. And I played my heart out.”
Macfie opened with two-over 74, was third after a second-round 68 – behind leader and Yorkshire team-mate Ben Schmidt, of Rotherham – and then shot 70 69 in the last two rounds.
“I didn’t try and push too hard,” continued Macfie, “I just gave myself chances and didn’t put myself under too much pressure.
“It was really exciting coming down the stretch, Ben was playing well, Tiger (Christensen from Germany) was doing well a couple of groups ahead. It was a pressure situation, but I came out on top.”
Christensen was runner-up on five under, followed by Schmidt on four under.
Macfie’s Lindrick club-mate Bailey Gill tied for sixth in the Lytham Trophy (70 75 70 76). The Walker Cup prospect finished two places above county team colleague Ben Hutchinson, of Howley Hall (69 71 77 75).
Wallasey’s Joshua McMahon shot 71 73 73 71 to win by one stroke from three players.