The Mariners did not look back after Carl Finnigan opened the scoring after just 20 seconds in front of a crowd of more than 1,400.
Gavin Cogdon quickly made it two and he added a third before the half-hour mark to make the points as good as safe.
Shields saw the game out effectively to ensure they will play in next season’s Evo-Stik Premier Division as their remarkable ascent up the football pyramid continues.
They could not have started any better against Glossop, with Finnigan finishing off a flowing move after the hosts won the ball from kick-off.
Cogdon got in behind on the right and squared for his strike partner, who made no mistake from close range.
It was Cogdon’s turn to get on the scoresheet in the eighth minute, with in-form Lee Mason at the heart of the move which led to the goal.
He drove forward and played a superb reverse pass to Cogdon, who brought the ball a bit further forward before firing in low via the post.
Shields played some terrific football in the first half, though Glossop did have some moments of their own as they tried to fight back.
Benjamin Richardson was their biggest threat, and he forced Liam Connell into a good low save in their first real opportunity of the game.
The home side started to dominate again after that, and almost netted their third when a Julio Arca cross from the right was brilliantly cleared off the line.
Mason also had two efforts blocked before Cogdon added the third goal in the 29th minute.
He twisted and turned in the box before finding the net via a deflection as he continued to cause the visitors no end of problems.
Shields threatened to run riot in the remainder of the first half, but Glossop did well to keep the score down.
At the other end, Craig Baxter did superbly to block from Richardson, who was also denied by Connell.
The Mariners were undoubtedly the team in the ascendancy, though, and they almost went four up when a Robert Briggs free-kick from deep was headed towards goal by Finnigan but brilliantly tipped over by goalkeeper Russell Saunders.
Cogdon went close to scoring his hat-trick on the stroke of half-time, but his effort from the edge of the box was deflected just past the post.
Shields were not as free-flowing going forward in the second half, but rarely looked under any real threat.
Cogdon and Finnigan continued to link up well, and they almost combined for a fourth goal when Finnigan played the ball to his team-mate, who saw a low shot saved by Saunders.
Baxter volleyed over from a Finnigan cross soon after, while at the other end, Shields twice somehow scrambled the ball to safety just as Glossop seemed set to pull a goal back, with Richardson missing an open goal.
The Mariners attempted to add some gloss to the scoreline in the closing stages, with substitute Louis Storey having a powerful effort blocked before Jon Shaw volleyed over.
Substitute Matty Pattison also went close after being played in by Briggs, but his shot across goal went inches wide.
Another close shave saw Cogdon cut inside from the left and fire just wide, and Finnigan was unlucky to see another effort palmed away by Saunders.
There could have been more goals, but three were more than enough for Shields.
They are on their way up again.
SOUTH SHIELDS: Connell, Baxter, Lough, Shaw, Morse, Arca (c) (Storey 57), Richardson, Briggs, Cogdon (Sullivan 76), Finnigan, Mason (Pattison 46). Subs not used: Woolston, Holmes.
Goals: Finnigan (1), Cogdon (8, 29).
WORDS: Daniel Prince. IMAGE: Kev Wilson.