The club's Academy teams recorded two 6-0 victories on a successful afternoon of action on Wednesday.
The young Mariners maintained their position at the top of both the National League Under-19 Alliance and Youth Development League with the thumping wins over Pontefract Collieries and Morpeth Town respectively.
The ECFA Cup match against Barnsley College, meanwhile, was postponed after Shields' opponents were left unable to travel to the North East because of the weather conditions.
Five of Shields' goals against Pontefract were scored in the second half, with Nathan Kidd (2), Alex Thompson, Bailey Rhodes, James McGeorge and Olly Cresdee on the scoresheet.
Head of professional development Jon Shaw said: "The lads started really brightly and scored a goal very early in the game, but as can sometimes happen, it seemed to have a negative effect and the feeling was the goal may have come too soon.
"They perhaps took their foot off the gas a little bit but after a few stern words at half-time from the coaching staff, when they were leading 1-0, they dominated the second half and ran away with the scoreline.
"It was another good result and good performance overall, but they need to learn from a first half like that and be more ruthless when they score an early goal.
"You have to go for the kill and keep pushing, because otherwise you give teams the opportunity to turn games around and make life difficult for you.
"The players responded in the right way in the second half and the table is looking very healthy."
It was a different story in the Youth Development League, meanwhile, with all six of the Mariners' goals against Morpeth coming in the first half.
They were spread between five players, with Frazer Barker (2), Jack Waller, Josh Leonard, Ashton Wright and Steve Luaba the marksmen for a team led by Shaw and Blair Adams.
Shaw added: "It was the other way around in this game, because the lads were outstanding in the first half and dominated it.
"They kept their foot down and we were encouraging them to continue pushing and creating opportunities.
"Sometimes it can be difficult when you're so far ahead at half-time to keep challenging yourself, and that proved to be the case.
"Morpeth didn't really threaten our goal, but some slightly bad habits crept in and there were more lessons to be learned.
"On another day we might have let our opponents back into the game, but the lads defended well and worked extremely hard out of possession, so it was another positive match for them.
"The team is top of that league too and rightly so with the way they have been performing on Wednesday afternoons."