Twice Blues had to fight back at The Lamb, on Tamworth's new artificial turf. And twice they did so.
The home side led from the 20th minute through Greg Mills.
Blues got on level terms after substitute Ronan Hale turned the ball round into the box for Lubala, who showed fine composure to steady himself and commit a defender to ground before finishing (56 minutes).
But Richard Beale's side fell behind again when Louis Briscoe scored with a long-ranger in the 63rd minute.
Blues strived hard to wrestle the ascendancy back and it turned out to be a rescue act, in the second minute of added-time.
Josh Martin hit a searching ball towards Hale, who had set off on a run down the left channel. Hale got the ball into Lubala who again finished with aplomb from inside the box.
Blues Under-23s return to action in PDL 2 at Nottingham Forest on Tuesday evening.
Blues: Weaver, Baba, Seddon, Cleary, Martin, Cooper (Mbunga 84), O'Keeffe, Maxwell, Wes McDonald, Lubala, Popa (Hale 54). Not used: Trueman, Matt McDonald.