Our reserve team have been beaten 2-1 by Norwich City at Carrow Road on Monday night.
A strike from winger Ishmael Welsh gave Hammers a half-time lead but the hosts fought back to score twice after the break and seal all three points.
Coach Kevin Keen named a young side for the trip to East Anglia, with young striker Hogan Ephraim the only outfield player possessing first team experience, although goalkeeper Jimmy Walker provided some welcome seniority between the sticks as he continued his comeback from injury.
Hammers made a bright start and might have been 2-0 up inside the first five minutes. Winger Kyel Reid crashed a shot against the post from just outside the penalty area, then James Tomkins almost converted with a powerful header that Norwich goalkeeper Lewis did well to keep out.
After Walker had made a smart stop to deny Ryan Jarvis, the visitors took the lead on 27 minutes, when Reid's cross from the right found Welsh, who controlled and finished well from 12 yards out.
Hammers continued to impress before the interval, but the hosts drew level just minutes after the restart when substitute Robert Eagle fired in a fierce volley from the edge of the penalty area that took a deflection on its way past Walker.
On 63 minutes, the Canaries netted what proved to be the winner, as Jarvis skipped down the right and fired in a low cross that was turned into his own net by skipper Darren Blewitt - at 20 the oldest outfield player in the Hammers side.
Walker was called into action again on a couple of occasions to prevent the hosts from extending their lead, proving that he is well on his way back to full fitness, while Hammers might have grabbed a point late on, but substitute Ryan Andrews headed over from close range.
Hammers: Walker; Henry, Fitzgerald, Tomkins, Blewitt; Reid, Cowley, Collison, Welsh (Andrews 58); Hines, Ephraim. Subs unused: Blackmore, Hales, Widdowson.