But the Lindrick member can take a lot of positives from his sixth-placed finish in England Golf’s flagship stroke play event - plus silverware in the form of the George Henriques salver awarded to the leading Great Britain & Ireland player aged under 20.
Playing in the final group with the eventual winner, Ireland’s Cormac Sharvin, the 19-year-old shot a closing one-over-par 73 for a three-under-par 285 aggregate (70 76 66 73).
“It’s the first time I’ve been in this position and I’m really pleased with the way I played under pressure,” said Yorkshire county player Thomson, who was one under through 11 holes of his final round, but shed shots at both 12 and 18.
Huddersfield’s Nick Marsh continued his pattern of alternating indifferent rounds with below-par scores, shooting his second 69 in the space of three days.
He was under par both going out – 35 – and coming home – 34 – with five birdies and two dropped strokes in his round.
His 291 total (75 69 78 69) tied him for 23rd place.
Bedale’s Daniel Brown had produced three consecutive scores of 73, but could not find a birdie all day while registering five bogeys and one double bogey. He placed tied for 50th on 298 (73 73 73 79).
Sharvin finished on seven under par, a stroke ahead of fellow Irishman Gavin Moynihan, who closed with a six-under par 66, and three ahead of another Irishman Jack Hume, Lancashire’s Paul Kinnear and American Charlie Danielson.