Pat McCormack suffered heartbreak in his bid to become only the second British male boxer to win a world amateur title in Chelyabinsk.
The Birtley 24-year-old dropped a unanimous decision to Russia's Andrei Zamkovoi after their welterweight final was stopped prematurely due to a cut.
McCormack had been bidding to emulate Frankie Gavin, who became the first British world champion with victory in Chicago in 2007.
An accidental clash of heads midway through the second round led to McCormack sustaining a bad cut and having to go to the judges' cards.
McCormack said: "It's been a good week for me and the team but I am gutted with how it ended.
"It is all about Tokyo now and I feel that me and the rest of the team are in good shape and can be confident as we look forwards to the Olympics next year."
As well as McCormack's silver medal, Great Britain ended the tournament with two bronze medals for Peter McGrail and Ben Whittaker.
