The reserve team was held to a 1-1 draw at Watford on Wednesday evening.
Kevin Keen's troops were left cursing their luck again as, for the second time in the space of three days, they conceded an equaliser late into stoppage time at the end of 90 minutes.
Following the 1-1 draw with Fulham on Monday night, Hammers again fielded a team consisting mainly of under-18 players, along with two schoolboy defenders - Bondz Ngala and Robbie Blackwell.
However, there was some senior experience in the side - thanks to the inclusion of Keen himself, who filled in at right-back following the late withdrawl of trialist Jack Haverson.
Just as they did against the Cottagers on Monday, Hammers started brightly and this time were rewarded for their attacking first-half display - taking the lead on 23 minutes.
Kyel Reid's surging run down the left ended with a low cross to the edge of the penalty area, where striker Zavon Hines (pictured above) controlled and found the net with a superb finish.
The hosts used their strength and experience to fight their way back into the game in the second half, but Hammers fought on bravely and, after showing great determination in the final 10 minutes, appeared to have done enough to hold on for all three points.
However, the cruel hand of fate struck for the second time in the space of 48 hours as the game entered stoppage time, with Watford scrambling a scrappy equaliser following an untidy goalmouth scramble.
Hammers: Bywater; Keen, Ngala, McKie, Blackwell; Ephraim, Collison, Baradji, Reid; Jeffery (Hunt 70), Hines. Subs unused: Blackmore, Sears, Stanislas.