The midfielder scored with his first touch, moments after coming on midway through the second half at a wet and windy Mazuma Stadium.
It meant the Shrimps made it back-to-back wins against Newport after victory in last season’s promotion play-off final.
In came Adam Phillips and Arthur Gnahoua, replacing Toumani Diagouraga and Wes McDonald who were both dropped to the bench.
The scale of change since the teams’ last meeting at Wembley, 159 days earlier, was illustrated by the starting line-ups.
Only three of the 22 who started at the national stadium began the return meeting five-and-a-bit months later; Cole Stockton for Morecambe and Mickey Demetriou and Aaron Lewis for the visitors.
With a gusty wind behind them in the opening half, it was the Shrimps who began on the front foot with Alfie McCalmont seeing two early shots deflected behind.
Stockton was unable to get sufficient purchase on Greg Leigh’s cross and Jonah Ayunga turned another effort off target.
Not that it was entirely attack against defence in the opening 15 minutes as Newport had some bright moments.
Finn Azaz saw a shot blocked and Jake Cain had an effort pushed away by Jokull Andresson.
The game began to settle down after that, though too many of Morecambe’s passes were caught by the wind and drifted away from the intended target.
For their part, Newport looked comfortable in possession and had the better of the few remaining opportunities before the break.
Andresson clawed away Dom Telford’s shot before Azaz had an effort deflected narrowly wide of the keeper’s right-hand post.
With torrential rain posing an added challenge after the break, both sides took it in turns to attack with Newport seeing Lewis and Cameron Norman off target from distance.
Telford did likewise, though Andresson was called into action to tip away Oliver Cooper’s shot with the Morecambe defence backing off him.
Stockton had been Morecambe’s likeliest source of a goal, seeing one effort held by Joe Day and another shot flash over.
In response, Robinson called Wildig off the bench and was rewarded almost instantly.
Callum Jones sent a ball in from the right-hand side and Wildig, in acres of space, found the net in clinical fashion.
Back came Newport with Scott Wootton blocking Telford’s shot and Courtney Baker-Richardson’s acrobatic effort deflected behind.
They also brought on former Shrimp Kevin Ellison, who scuffed an effort straight at Andresson in seeking a repeat of his goal when the teams met last season.
Wildig chipped narrowly wide from 40 yards but Morecambe were grateful to Andresson again as he clawed away another attempt from Azaz.
However, they managed to play out five minutes of added time without real alarm to take their place in round two, played on the first weekend in December.
Morecambe: Andresson, McLaughlin (Cooney 83), O’Connor, Wootton, Leigh, Phillips (Wildig 67), Jones, McCalmont, Ayunga, Stockton, Gnahoua (Diagouraga 79). Subs not used: Letheren, McDonald, Delaney, Mensah, Gibson, Harrison.
Newport County AFC: Day, Norman, Clarke, Demetriou, Lewis (Collins 83), Wilmott, Cain (Ellison 77), Azaz, Cooper (Fisher 90), Telford, Baker-Richardson. Subs not used: Townsend, Haynes, Upson, Dolan, Abraham, Missilou.
Referee: Chris Sarginson.
Thanks for reading. If you value what we do and are able to support us, a digital subscription is just £1 per month for the first two months. Try us today by clicking here