Young Canaries dealt late blowWEST Ham's Jerry Amoo scored the winning goal two minutes from time to consign Norwich City's Under-18s to a 1-0 defeat at Colney.
The midfielder pounced in the box to snatch the three points - a harsh finale for a Canaries side that had looked the most likely to get the winner.
In a quiet first half, it was the visitors who had the better chances through Amoo and captain Manny Onariase.
City goalkeeper Marcus Beauchamp then produced a stunning save to keep out Joe Powell's header on 58 minutes just prior to Djair Parfitt-Williams somehow nudging an effort wide from close range.
Substitutions changed the game for Jerry Gill's side, however, and they were the more dangerous side in the final 20 minutes, with George Couzens and Benny Ashley-Seal going close to breaking the deadlock.
A fingertip from Hammers 'keeper Sam Howes prevented Jake Simpson from tapping in, before West Ham raced up the other end and got the decider against the run of play.
Oscar Borg beat Jamal Lewis to the ball and crossed from the byline, with Beauchamp palming it into the path of Amoo, who took his chance by firing high into the net.
It meant City undeservedly came away with nothing, and they will hope for more fortune when they visit Aston Villa on Saturday November 8 (12pm).
Gill said afterwards: "The substitutes seemed to make a big difference for us, they lifted the intensity in the game.
"It was quite a mundane game, there wasn't too much in it and there wasn't very many chances. West Ham have come away with the win but I don't think they really deserved it. We were in the ascendency at the end."
FULL-TIME: Norwich City 0-1 West Ham United
GOALS: Hammers: Jerry Amoo (88)
NORWICH CITY: Beauchamp; Efete (c), Fox, Burgess, Boateng; Black (Sambu 68), Grant; Lewis, Cantwell (Simpson 77), Ashley-Seal; Eaton-Collins (Couzens 62). Subs not used: Hale-Brown (GK).