St Albans were relegated as they only managed a draw in a game that saw Ram Marwa and Ludovic Quistin sent off.
The result left Saints 11 points from safety with three matches remaining, ensuring their stay in the Conference will last only one season.
St Albans took the lead when Leon Archer found Lee Clarke, who shot past Jose Veiga in the Tamworth goal.
But Tamworth drew level after 78 minutes with a Graeme Law penalty after Ram Marwa fouled Jon Stevenson.
Tamworth: Veiga, Briscoe, Bains, Weaver (Heslop 61), Friars (Stevenson 73), Law, Smith, McGrath, Taylor, Edwards (Quistin 84), Atieno.
Subs Not Used: Bampton, Williams.
Sent Off: Quistin (90).
Goals: Law 78 pen.
St Albans: Bastock, Marwa, Deen, Ben Martin, Seeby, Buari (Lopez 90), Cracknell, Davis, Cousins, Clarke, Archer.
Subs Not Used: Hann, Perks, Basse, Roddis.
Sent Off: Marwa (89).
Booked: Davis, Buari, Archer, Marwa, Clarke.
Goals: Clarke 15.
Ref: S Procter-Green (Lincolnshire).