Clinical hat-trick steers South Shields back to winning ways at Bamber Bridge
Gilchrist's first treble for the club was an important one at Sir Tom Finney Stadium against a Brig side which had started the season with a win and a draw.
Shields knew the importance of maximum points after a 3-1 home reverse to Radcliffe four days earlier left them playing catch-up in the early Pitching In Northern Premier League table.
Two goals were traded inside the first 16 minutes, with Gilchrist finishing from close range early on before Matt Dudley equalised for the hosts.
Gilchrist netted again after outstanding work from Darius Osei 12 minutes before the break and completed his hat-trick on the hour mark to take his tally for the Mariners to 30 and move his side up to third in the league.
Phil Turnbull and Will Jenkins were introduced to the starting line-up by joint managers Lee Picton and Graham Fenton, but it was Brig who had the first effort of the game as Danny Forbes turned inside the area and had a shot blocked by Dillon Morse, who also got in the way of a follow-up strike from George Thomason.
It took Gilchrist just four minutes to make his mark on the game though as he banished his frustration from four days earlier against Radcliffe, when he hit the woodwork three times.
Darius Osei swung in a cross from the right flank which was headed across the area by Jon Shaw to his defensive partner Morse, whose effort was parried by home goalkeeper Danny Roccia. He could only push the ball back out into his six-yard box, though, where Gilchrist was on hand to convert from close range.
It did not take long for Bamber Bridge to draw level, with their equaliser arriving in the 16th minute.
Some neat interplay on the inside-left of the box concluded as Callum King-Harmes laid the ball off to Dudley and he stroked it into the bottom corner, leaving Myles Boney with no chance.
The hosts had similar joy down their left flank as they searched for a quickfire double, but as Thomason shaped to shoot from a similar position to the one Dudley scored from minutes earlier, Callum Ross charged him down to make the block and underline Shields' determination not to suffer back-to-back defeats.
Turnbull was a reassuring presence in midfield for the Mariners as he made his first start of the season, albeit in a slightly unfamiliar role on the side of a diamond. He almost assisted a second Gilchrist goal as he lifted a ball down the left and, with Roccia charging well out of his box, the Shields striker hit an effort which struck the goalkeeper and spun towards goal via a bounce on the wet surface before it was scrambled clear.
Forbes tested the palms of Boney with a well-struck shot from the edge of the box but Shields regained their lead on 33 minutes thanks to a sublime link-up between Osei and Gilchrist.
A tremendous control and turn by Osei on the left saw play open up for him and when he fizzed a dangerous low cross into the six-yard box, Gilchrist got in front of his defender to flick the ball home with a deft finish.
There were two half-chances for Brig to equalise for a second time before half-time, but Boney was equal to Forbes' strike and although he later had to scramble across his goal as King-Harmes curled in a dangerous cross, the ball was ultimately off-target.
Macaulay Wilson had the home side's first effort of the second half but although his free-kick from 20 yards was low and awkward, Boney clung onto it at the second attempt. There was another heart-stopping moment for Shields as Matt Lawlor's menacing cross from the right just evaded a meaningful touch.
Shields went close to extending their lead when Osei held the ball up well and played it to Briggs, whose effort with the outside of his right foot curled into the side netting.
On the hour mark, though, Gilchrist was very much on-target as he registered his and Shields' third of the afternoon in ruthless fashion.
Alex Kempster, who performed admirably in an unfamiliar left-back role, motored down the left flank and his cross fell perfectly into the path of Gilchrist, who guided it into the corner of the net to ease any Mariners nerves.
Although Bamber Bridge saw a lot of the ball in the final half-hour, they were unable to test Boney as their visitors largely kept them at arm's length.
Shields will now take a short break from league action when they travel to Southport in the FA Cup on Tuesday.
South Shields: Boney, Baxter, Kempster, Shaw (c), Morse, Ross, Turnbull, Briggs, Gilchrist (McCamley 87), Jenkins (Verstraaten 56), Osei (Hodgson 78). Subs not used: Agnew, Croft.
Goals: Gilchrist (4, 33, 60).