The only goal of the game was scored after just 13 minutes when Ryan Leek forced the ball home from just four yards out following a corner.
In truth, it was the visitors' that made the better start and they twice went close before taking the lead.
It took Blues until the quarter-hour mark before their first attempt, when the lively Kyle McFarlane saw his shot deflected into the arms of the goalkeeper.
The Blues winger then headed over, before having a curling effort well saved.
Minutes before the break Blues looked to have found a way back into the contest, but Alex Jones' goalbound effort was cleared from just in front of the goal line.
Blues improved substantially in the second-half and fashioned a number of openings, with Charlie Cooper firing a yard wide from a free-kick, Beryly Lubala shooting just over the bar and Ronan Hale seeing a couple of attempts blocked in the area.
But Wolves hung onto their lead and shaded what had been a fairly even contest.
Blues Under-21s: Trueman, Harding, Martin, Seddon (O'Neill, 60), Bernard, O'Keeffe (Lubala, 75), Baba, Cooper, McFarlane, Hale, Jones (McDonald).
Subs not used: Weaver, Mbunga.