Gavin Cogdon scored the winner for the second time in a week as South Shields triumphed brilliantly at champions Shildon.
The Mariners produced arguably their best performance of the season so far to win 1-0 at Dean Street.
Having had much the better of the first half, Shields were further boosted by the sending off of home right-back Jamie Harwood.
They took full advantage of their one-man advantage as Cogdon fired in to delight a huge away support.
Shields were on the front foot from the first whistle, with Cogdon almost scoring within the first minute as he charged down goalkeeper Nick Liversedge, who just managed to clear it to safety.
Liam Connell was on hand to deny Shildon’s Billy Greulich-Smith, who fired in a powerful low effort, but Shields nearly took the lead when Robert Briggs and David Foley almost slid in a cross, while David Carson had a shot tipped wide by Liversedge.
Shildon possessed dangers of their own, and Lewis Wing hit the post with a free-kick and also went close with a shot from distance.
Briggs had a low header excellently saved, while Foley had a glorious chance to put Shields in front when Julio Arca brilliantly played him in, only to hit his shot well over.
Cogdon and Luke Hannant went close before the half-time break, and after that, the same pattern continued.
Hannant hit a half volley not far wide and Briggs went agonisingly close when his free-kick struck the inside of the post and then hit the other post before bouncing to safety.
Harwood was shown his second booking for bringing down Foley, and the Mariners took the lead in the 69th minute.
Substitute Andrew Stephenson found Briggs, and his excellent through ball presented a good chance for Cogdon, who made no mistake as he rifled it past Liversedge.
Cogdon had scored a dramatic injury time winner on Saturday as the Mariners beat Ashington 3-2.
Foley went close and Shields continued to control the game until a heart-stopping moment two minutes into added time.
A free-kick was lofted forward, flicked on and then hit several feet into the air, before coming down and being scrambled to safety.
A draw would have been an extremely harsh outcome for Shields, though, who remain second in Northern League Division One and go into Saturday’s trip to FA Vase holders Morpeth Town full of confidence.
SOUTH SHIELDS: Connell, Baxter, Arca, David Carson, Morse, Shaw, Hannant (Phillips 85), Scroggins (c) (Stephenson, 59), Cogdon (Finnigan 71), Briggs, Foley. Subs not used: Riding, Smith.
Goal: Cogdon (69).