It stayed that way until the hour mark when Birmingham levelled from the penalty spot but that goal only served to rejuvenate the lads and they were soon in front again with a fine solo effort from Danny Hutchins.
Andros Townsend produced a clinical finish for 3-1 after 75 minutes and further chances came and went before City reduced the deficit with five minutes left.
The win makes it just one defeat in the lads last seven league games.
Spurs U18s: Butler, Smith (C Butcher, 55), Hutchins, Kasim, Berchiche, Mtandari, Fraser-Allen (Hutton, 65), Parrett, Olsen, Mason, Obika (Townsend, 60). Unused subs: L Butcher, Cox.
Our Under-18s made it four matches unbeaten with a 3-2 success against Birmingham City in the FA Premier Academy League on Saturday.They went ahead early against the Blues with Alex Olsen tapping home from Ryan Mason's cross with only two minutes on the clock.