The Stoke Park GC player added the trophy to the English Amateur title he won in August and was alone is shooting par for the four-round championship, his scores of 67, 70, 73 and 70 earning a level-par total of 280.
He was pushed hard over Sunday's closing 36 holes by runner-up Connor Graham of Scotland, who finished one-over on 281, with Ben Quinney two shots further back in third.
Jamie van Wyk led the way among those representing the host club, tied for 18th on 290 as 45 players survived the cut after the first two days.
The Fairhaven Trophies carry similar prestige in junior golf and also returned post-pandemic last weekend.
The winner of the boys' trophy at Fairhaven was England's Ben Brown with a 10-under total of 278 (71, 66, 69, 72), winning by five shots from Dylan Shaw-Radford.
Ben, from Northallerton, Yorkshire, particularly liked the par-five opening hole, on which he scoring an albatross and an eagle.
The girls' trophy was won by Katie Potts of Belfast with a one-under total of 299 (77,77,73,73), two shots ahead of runner-up Isla McDonald-O'Brien.
Shaw-Radford was also a member of the England Three team which won the Fairhaven Nations Cup. He and teammates Amelia Wan and Hugh Adams scored 278.
Florence Barker and Felicity Lawson won the Scott Leggatt Foursomes event at Knott End with 34 points and progress to the divisional final at Penwortham in June.
The club foursomes was won by Muriel Naden and Brenda Braithwaite with 38 points
For two years Knott End Ladies have raised money for local charity The Rainbow Hub, which helps children with neurological issues and supports their families.
GC have spent the last 2 years raising money for The Rainbow Hub.
Lady vice-captain Jayne Emmington and former lady captains Felicity Lawson and Brenda Braithwaite recently visited the Hub to present a cheque for £2,100.
This week's top tip from Alastair Taylor, teaching professional at Herons' Reach GC, is to stay down at impact.
Golfers who mishit a shot often say they lifted up through impact when they needed to stay down. This may be true but they need to understand why they feel they have lifted up.
When a player assumes a decent posture to swing the club around the body, the aim is to maintain the angles created at address through impact with the ball.
Players fail to do this because they move their hips towards the ball at the start of their downswing. The body then rises and comes out of posture, creating issues with strike, club-path and club-face control.
If that applies to you, then you need to feel your hips moving back and away from the ball when starting your downswing, lowering your chest height. This gives you room to swing your arms and means fewer compensations through impact, leading to better ball-striking and control.
Contact Ali at [email protected] or check out his YouTube channel AliTaylorGolf for more free tips.