True, Coventry sent their under-21s to face Town, but they are full-time professionals, with some already having played first-team football.
And, for the vast majority of the match, they were second best.
Town had the perfect start when man of the match Edwin Ahenkorah netted his ninth goal of the season after just two minutes and though George Thomas levelled from a penalty on 15 minutes, Carl Adams’ men always had the edge.
Seven minutes from time, Ahenkorah’s corner from the right was only partially cleared and midfielder McGrath steamed forward to smash a low shot through a ruck of players into the net.
Stratford created the clearest openings throughout , but two wonderful saves, three efforts cleared off the line and another striking the woodwork meant they could not turn their superiority into goals.
It was a fast paced first half, with play ebbing and flowing. Coventry looked a threat with their sharp breaks but Stratford more than matched them in terms of possession and created the more incisive moves.
Within two minutes, the hosts had the lead when Liam Francis’s long pass down the right flank sent Ahenkorah scampering forward. The Town top scorer left two defenders in his wake and then rifled a low drive into the bottom corner.
Town had already threatened when Francis’ shot was cleared off the line by Cian Harries inside the opening minute and most of the play was directed towards the Sky Blues goal.
Then Ahenkorah and Francis just failed to get any contact on teasing crosses.
But the first real effort on Town’s goal led to the Coventry equaliser on 15 minutes.
Jay Albini set up Lateef Elford-Alliyu but his shot smacked into McGrath and, on the say-so of the assistant referee, referee Grant Taylor pointed to the penalty spot for handball. Thomas, who has played first-team football, stepped up and coolly tucked the spot-kick into the bottom corner.
It failed to dent Town’s confidence, though, and Ahenkorah was proving a real handful for the Coventry defence.
Sky Blues keeper Corey Addai was certainly the busier, and two wonderful saves kept it level at half-time. The first was a full-length tip over from a Robbie Thompson-Brown free-kick which looked destined for the top corner and then Addai leapt to push aside a downward Francis header from Thompson-Brown’s corner.
Thomas’s trickery provided the visitors with their most inventive moments,but Bassala Sambou and Elford-Alliyu failed to capitalise on his good work.
Town made two substitutions at half-time, with Alex Price limping off with a leg injury, and Thompson-Brown going off and Richard Gregory and Jamie Sheldon coming on.
Gregory, playing his first Town game since the opening day of the season, was immediately into the action. The striker’s hooked shot flashed just over and then he found space to head McGrath’s corner goalwards, only for Harries to again nod the effort off the line.
Coventry were rarely able to test the Town defence, with the ever-improving Emmitt Delfouneso again shielding the backline.
Town were starting to wonder whether it was going to be their night when Ahenkorah’s curling effort thudded against the post and Dior Angus failed to convert in front of an inviting goal.
But seven minutes from time Town had their deserved goal through McGrath’s sharp-shooting and his second goal since joining from Rushall Olympic.
So Town, perennial underachievers in knockout football in the last few season, have won a cup-tie. It was as one Sky Blues fan admitted ‘men against boys.’
TOWN: (4-2-3-1) Kemp; Stringfellow (Moran 77), Francis, Simpson, Westwood; McGrath, Delfouneso; Angus, Price (Gregory HT), Thompson-Brown (Sheldon HT); Ahenkorah. Subs not used: Cutts, Faulkner.
COVENTRY: (4-2-3-1) Addai; Kelly-Evans, Ford, Harries, Leahy; Shipley, Stevenson; Albini (Whitmore 58), Thomas, Sambou; Elford-Alliyu. Subs not used: Skuza, Smith, Bayliss, Hitchman.
Referee: Grant Taylor.
Bookings: Stratford: McGrath; Coventry: Ford.