Shields enjoyed almost total control from the outset at Mariners Park - after the game was delayed by half an hour because of problems with the floodlights.
When the match finally did get under way, it took just three minutes for the Mariners to take the lead.
Michael Richardson curled in a superb free-kick delivery from the left, and Aycliffe defender Daniel Mitton could only head the ball into his own net.
After taking an early advantage, Shields never looked likely to let the visitors back into it.
Jamie Owens flashed an effort over for Aycliffe, but that was a rare opportunity.
Shields fielded a side showing seven changes from Saturday’s win at Ryhope Colliery Welfare, and one of those who kept his place was Barrie Smith in the centre of the park.
He put in an impressive performance, and sent a half volley narrowly wide as he tried to extend the Mariners’ advantage.
The second goal came in the 24th minute for Shields after a fine team move, which ended when Craig Baxter’s low ball in the box was slid home by Jordan Blinco on his home debut.
It was Blinco’s third goal for the Mariners in two games, and he almost had another when he went on a strong run before seeing his low effort tipped behind by former Shields goalkeeper James Winter.
Just more than 10 minutes before the break, the points were as good as wrapped up when Wayne Phillips’ inch-perfect cross from the right was headed in by Romanian defender Iulian Petrache.
Smith was inches away from making it 4-0 shortly before half-time, but his effort was deflected not far past the post.
The second half was a lesson in keep ball from the hosts as Aycliffe sat deep.
Richardson and David Foley both had shots saved by Winter, while the visitors were reduced to 10 men when Scott Howes received a second booking.
Shields’ dominance of the ball was even more apparent after that, and they went close a number of times in the closing stages.
Foley went the closest as he stabbed an effort narrowly wide from the edge of the box.
It looked all set to end 3-0, but with the last kick of the game, Richardson powered a low free-kick into the net to make the scoreline even more comfortable.
The Mariners are now 11 points behind North Shields at the top, and play one of their four games in hand tomorrow when they travel to Sunderland RCA.
SOUTH SHIELDS: Jameson, Baxter, Callaghan, Lough, Petrache, Arca (c) (Storey 59), Smith, Phillips, Blinco (Stephenson 68), Richardson, Foley. Subs not used: Connell, Cogdon, Morse.
Goals: Mitton own goal (3), Blinco (27), Petrache (34), Richardson (90+4).