Jonny Margetts's first-half brace and Quevin Castro's 90th-minute strike condemned South Shields to a second-consecutive away loss in the Vanarama National League North.
The Mariners travelled to Norfolk on the back of a 10-day rest from football after the previous fixture away to Banbury United was postponed.
Shields Head Coach Elliott Dickman made two changes to the side that beat Scunthorpe United, as Jed Abbey and CJ Clarke came in for the suspended Robert Briggs and Will Jenkins.
King's Lynn had one change from their stalemate away to Alfreton, Jonny Margetts started in place of Greg Taylor.
Margetts opened the scoring for the Linnets on the 13th-minute mark after Ben Stephens pressed Myles Boney to lose his footing, pinching the ball and squaring it to Margetts for a tap-in.
National League top-scorer Paul Blackett would have a handful of chances in the first half, but the woodwork would deny his closest efforts.
Margetts would find the back of the Shields net again in the 41st minute with a well-hit volley into the top left corner to double the host's lead.
Blackett would have the last chance of the first half as his acrobatic effort would fly just shy of the target.
The Shields number nine extended his goal tally to 22 a few moments into the second half with a cool finish into the far corner in the 47th minute.
The Mariners looked to grow into the second half but with every chance came a lack of finishing touch or some expert defending from the Linnets.
King's Lynn substitute Quevin Castro's shot from outside the box would fire in off the post in the 90th minute to restore the Linnet's two-goal advantage and to kill off any hopes of a late comeback from Shields.
The result leaves the Mariners in 12th place, four points off the play-offs with a game in hand over five of the teams above them in the National League North.
South Shields: Boney, Hunter, Clarke (Savage 69'), Broadbent (Sloan 45'), Morse, Smith (C), Heaney, Abbey (Gomes 85'), Blackett, Woods, Stephenson.
Subs not used: Sloan, Fletcher, Seymour
Goals: Blackett (47')
Attendance: 834