South Shields start 2022 with 1-0 win over Scarborough Athletic at 1st Cloud Arena
McGowan struck midway through the first half as the Mariners produced a solid performance and displayed impressive character in front of a crowd of 2,238.
There were some nail-biting moments in the closing stages but Shields saw the game out to climb to third in the Northern Premier League and within two points of leaders Matlock Town.
Graham Fenton named an attacking line-up as the hosts aimed to return to winning ways, with Darius Osei reintroduced to the team after serving a three-match suspension.
But it was Scarborough - victorious at promotion-chasing Bamber Bridge and Warrington Town in their previous two away games - who created the first chances, with defender Will Thornton having a powerful drive deflected over and Jacob Day heading over from the resulting corner.
Cedric Main had caught the eye in Shields' 2-2 draw with Whitby Town five days earlier and he was again prominent here. He signalled his intent with some direct play in the 10th minute as he brought the ball inside from the left before zipping a low effort which Ryan Whitley did well to hold in the Boro goal.
Main was at the heart of what proved to be the only goal, which arrived in the 23rd minute.
The Mariners were rewarded for patient build-up play which began with Myles Boney and concluded when JJ Hooper found Main and he showed impressive control before playing in McGowan, who produced a composed finish into the roof of the net to score for the third home match in succession.
Shields did not have it all their own way, though, and were reminded about Scarborough's threat as Simon Heslop's strike was blocked and Thornton fired over from close range with the goal gaping.
At the other end, Dillon Morse headed over from a corner and Main struck a low shot narrowly wide after again coming inside from the left.
The second half brought a more controlled performance from the Mariners, who had a good chance to double their advantage on 57 minutes when Main's scooped pass found Hooper, whose volley cleared the crossbar.
Osei later drew a save from Whitley, but Shields had to be alert defensively as Thornton had a header deflected wide and Boney was forced into a save from Watson.
The home side looked set to see out the remaining minutes with relative ease until Scarborough were presented with a golden opportunity six minutes into stoppage time when Kieran Glynn was played in on goal. There were sighs of relief all round when the forward flicked the ball wide.
Shields' victory was duly confirmed as they closed the gap at the top. Just three points now separate the top five sides in the division.
South Shields: Boney, Rose, Adams (c), Ross (Jenkins 56), Morse, Bodenham, Osei (Kempster 87), Lowe, Hooper, McGowan, Main (Tee 67). Subs not used: Shaw, Hodgson.
Goal: McGowan (23).