Grimsby Town blew League One leaders Plymouth Argyle away with a scintillating first-half performance to claim a fully deserved place in the second round of the FA Cup.

The Mariners fell behind to Adam Randell’s superb early goal but they were soon level through Andy Smith’s header from a corner.

Michee Efete completed the turnaround as his header finished a brilliant set-piece move from another corner, before Brendan Kiernan’s back-heel made it 3-1 and Anthony Glennon added a fourth in stoppage time before the break.

Kiernan went on to volley home his second of the game just before the hour to add extra gloss as Town provided the fireworks to start Bonfire Night with a bang and secure a thumping victory to boost confidence after two league defeats.

Four changes were made to the Grimsby starting XI following last week’s loss at Hartlepool United. Glennon, Alex Hunt, Otis Khan and Kiernan came into the team, with Niall Maher, Danny Amos, Lewis Richardson and Ryan Taylor making way.

Max Crocombe started in goal, with Efete, Luke Waterfall, Smith and Glennon forming the defence. Hunt and Bryn Morris sat behind Harry Clifton, Gavan Holohan and Khan in midfield, with Kiernan leading the line in attack.

Maher, Amos and Richardson were all named on an eight-man substitutes’ bench, where they were joined by Jamie Pardington, Shaun Pearson, Evan Khouri, Keke Simmonds and Jordan Cropper.

Plymouth’s league position made them the highest-ranked club at this stage of the competition and they were out to make that tell by reaching the second round.

Manager Steven Schumacher would look to the likes of strikers Sam Cosgrove and Ryan Hardie as the Pilgrims aimed to avoid being on the wrong end of a surprise result.

The visitors won an early corner when a cross from Joe Edwards was put behind by Hunt but as a swirling delivery came over from the right, the referee blew for a push and a Town free kick.

But it was not long before the deadlock was broken by Plymouth, as midfielder RANDELL drilled a powerful, low strike from 25 yards which beat Crocombe and nestled in the bottom-right corner of his net.

Town did not show themselves as an attacking force until the seventh minute, when Kiernan got to the by-line on the left and pulled the ball back. Nobody could apply a finish but the Mariners kept possession and worked it back, with Hunt eventually seeing a shot blocked for a corner after Holohan had played an intelligent through-ball for Kiernan.

Clifton then did well to chase the ball down and keep it in on the right, before his cross was cut out for a corner. And from the flag, the hosts were level, as SMITH got to the ball first at the far post and headed it beyond keeper Michael Cooper.

Town kept pressing and another opening almost came when Kiernan held the ball up well before finding Holohan inside the box, although his pull-back across goal was jut too far ahead of Khan and the visitors scrambled the ball clear.

A foul on Holohan brought a free kick inside the away half and it eventually led to a corner on the right. Glennon’s ball from the flag was headed clear but the hosts kept possession until a foul by Waterfall on defender Nigel Lonwijk.

After falling behind amid a shaky start, the Mariners had come roaring back into the contest and having got their equaliser, were now firmly on top as the 20-minute mark passed.

Plymouth were forced into the first substitution on 24 minutes when Conor Grant went down with an injury and was unable to continue. He was replaced by Bali Mumba.

An away corner soon afterwards was headed away by Efete, with the right-back also heading clear from a return ball into the box.

A foul on Efete near the right touchline brought another opportunity to get the ball into the danger zone on the half-hour but Glennon’s delivery was headed clear.

The home pressure continued when a Khan cross was deflected away for a corner after good play by Kiernan on the left. And this time, the Mariners made it count to complete the turnaround with a beautifully executed training ground move. Glennon played the ball short to Hunt and when it was eventually crossed into the box, EFETE looped a header over the keeper and into the far corner of the net.

Town kept attacking after taking the lead and a good run down the left by Khan went unrewarded, before Hunt started another attack as he found Kiernan down the left but the striker was unable to pick out a team-mate inside the box.

The Mariners did not have to wait much longer for a deserved third goal though, as Clifton looked up from the right on 39 minutes and pulled the ball back for KIERNAN, who flicked it past Cooper and into the far corner of the net.

A second Plymouth change saw James Wilson replace Dan Scarr in defence straight after the goal and Town were immediately on the hunt for another, with the keeper just beating Kiernan to Clifton’s long ball.

Holohan volleyed at Cooper after taking the ball forward from halfway as the relentless Grimsby pressure continued, with half-time approaching.

Six added minutes were played at the end of the first half and it was almost 4-1 as Kiernan beat his man to get into the penalty area before crossing for Khan, whose header was hooked clear off the line.

A foul on Hunt gave Town a free kick on the halfway line but after Efete had headed the ball from it on, the referee spotted an infringement by Kiernan.

Holohan won a corner as the hosts kept attacking but Glennon’s ball from the flag was headed away by Edwards. Town were not done though as they worked the ball back and after it was not dealt with inside the box, GLENNON pounced to beat Cooper for their fourth goal of an incredible first half.

Niall Ennis and Morgan Whittaker were sent on by the visitors ahead of the restart, with Will Jenkins-Davies and Cosgrove making way as they looked for an unlikely route back into the cup-tie.

Mumba won a corner within 30 seconds but Whittaker’s ball from the flag was too strong.

Kiernan then won a corner at the other end and from it, Town went close to making it 5-1 but Waterfall’s powerful header was brilliantly blocked on the line.

Khan was booked for a late challenge, before Mumba won another corner when his cross was blocked by Efete. Randell’s ball from the left flag was headed over the bar by Matt Butcher.

Whittaker tried his luck with a strike from 30 yards but Crocombe got down to make a comfortable stop, then Holohan could only shoot through to Cooper at the other end after being found inside the box by Khan.

Plymouth had looked brighter in the early stages of the half but their faint hopes of clawing their way back into the contest were put to bed once and for all just before the hour as the Mariners scored another fantastic goal. Clifton played the ball to Efete on the right and his cross picked out KIERNAN, who volleyed past Cooper in front of the Pontoon Stand.

A Glennon corner was headed clear at the near post, before a low ball from Mumba was missed by Whittaker as the visitors looked for a consolation. A corner came moments later but Waterfall was in the right place to head it away from danger.

Butcher was shown the yellow card for a foul which gave the Mariners a free kick in a dangerous position on the right on 71 minutes.

Glennon swung the ball towards the far post and it was headed behind for a corner, which beat everybody and went out for a throw-in.

Kiernan sent a shot wide of the far post after cutting in from the left in search of his hat-trick goal, before Caleb Roberts replaced Brendan Galloway as the visitors made another change with 15 minutes to go.

Town boss Paul Hurst made a triple-substitution soon afterwards as Richardson replaced Kiernan, Simmonds came on for Khan and Holohan made way for Khouri.

A penalty claim was waved away by the referee after Richardson went down inside the box, before a stoppage came when Efete was hit by what appeared to be cramp. He was replaced by Cropper for the last six minutes.

Simmonds sent a teasing ball towards the far post as Town looked for goal number six but nobody could get on the end of it.

Smith was booked for a foul on Hardie but Plymouth were unable to profit from the resulting free kick as the ball was played to Ennis and his cross was caught by Crocombe.

Clifton was barged over to give the Mariners a free kick on the right as the clock ticked into the 90th minute but nobody could get to Hunt’s delivery to apply a finishing touch.

Four added minutes were played and a free kick midway inside the away half brought another chance for Town to put pressure on Cooper’s goal but this time, they were unable to test the keeper.

The hard work had already been done though and the final whistle brought a big cheer from the 4,000-plus home fans around Blundell Park in appreciation of what had been an excellent performance from their side.

Town and their fans will now eagerly anticipate Monday evening’s draw for the second round, with attention also turning to Tuesday and the visit of Manchester City U21 for the final Papa John’s Trophy group match, with qualification for the knockout rounds at stake.