The Wire led 20-10 with tries from Charlie McKler (8 mins), Daniel Coop (27), Alfie Poles (45), and Jack Fallon (54), along with two conversions from Daniel Regan.
But Hull fought back with scores in the 59th and 68th minute to deadlock the scores, and with three minutes to go, full-back Owen Bartle laned the winning drop goal.
Wolves head of youth and Reserves head coach Ryan O’Brien said: “Despite the loss, there was actually a lot to like about our performance.
“We scored successive tries on two separate occasions but then just lacked the execution to see off a resilient Hull FC side.
“We got a few key moments wrong that impacted either the momentum of the game or the scoreboard, but they present valuable learning opportunities for our players that will stand them in good stead for the future.”
Wolves: Cameron Cooper; Jake Thewlis, James Duffy, Alfie Poles, Jack Fallon; Daniel Regan, Pat Irwin; Isaac Reid, Ben Hartill, Charlie McKler, Ewan Smith, Kian Stanton, Daniel Coop. Subs: Lucas Mulqueeney, Logan Raughter, James McGuire, Joe Bajer. 18th man: Tommy Rhodes.
The Reserves entertain Leeds Rhinos at Victoria Park Stadium on Sunday, kick-off 1pm.
Warrington Wolves Academy are away to Huddersfield Giants Academy at Dewsbury Rams’ Flair Stadium this Wednesday, kick-off 7pm.