The Mariners had been heavy favourites to beat the west Londoners, who only turned professional in the summer, but they struggled throughout to break their visitors down.

Grimsby had the better of the early stages but they were given a shock when a 25-yard screamer from midfielder Jamie Hand gave the away side the advantage with 19 minutes on the clock.

Town had been guilty of playing too many long balls in the first half but they improved after the break, creating several good chances and seeing Steven Watt hit the bar with a header.

But just as it looked like an equaliser might be in the offing, the Mariners were hit with a sucker-punch as Bradley Pritchard struck to give Hayes and Yeading a two-goal lead and seal the victory.

Alan Connell hit a late consolation goal after Watt had seen a header ruled out for offside but the result made it clear for Grimsby just how difficult life in non-league's top tier could be.

Neil Woods made just one change to the Town side that shared the spoils with York City in midweek, as skipper Lee Peacock missed out through illness.

His place in the starting XI was taken by right-back Dwayne Samuels, who came in for his competitive debut in the black and white stripes.

Michael Coulson moved from the right-wing role he occupied against York to fill in for Peacock up front, with Peter Bore taking up a more advanced position on the right and Samuels slotting in at full-back.

Kenny Arthur began in goal, with Samuels, Darran Kempson, Watt and Lee Ridley, who was captain for the day, making up the defence.

Bore, Michael Leary, Mark Hudson and Rob Eagle were the midfielders, with Connell lining up alongside Coulson in attack.

There was a welcome appearance for Charlie Ademeno on the Mariners bench after the former Crawley striker made a return to fitness ahead of schedule. He was joined amongst the subs by Scott Garner, Micky Cummins, Bradley Wood and Tom Corner.

Hayes and Yeading made their first ever trip to Blundell Park, just three years after being formed following a merger.

Their danger man was likely to be ex-Town loanee Ben Wright, who scored both goals in a 2-1 home win for Garry Haylock's side against Bath City last Saturday.

The Middlesex side would be looking to improve on their travels after a disappointing 5-0 reverse at Eastbourne in midweek.

Town kicked off, attacking the Osmond Stand end of the ground, but it was the visitors who had the first chance of the game when they won a free kick on the edge of the Grimsby area, only for Peter Holmes' delivery to be cleared by Watt.

The first attack from the home side saw Bore set off on a run down the middle before bringing in Connell and the move ended with Samuels seeing a shot deflected wide for a corner.

Grimsby were looking to play a direct, long-ball style of football in the early stages of the game, with Hayes and Yeading happy to sit back and head the ball away from danger.

Connell had a half-chance on 10 minutes after Bore had got in behind the away defence but the attempted chip from the former Bournemouth striker sailed harmlessly over keeper Lee Harrison's bar.

Bore then tried his luck from long range after Connell had won the header from a long kick by Arthur. Again, Harrison was not troubled as the low shot skimmed wide.

Grimsby had been well on top over the opening quarter of an hour but when the opening goal came on 19 minutes, it was the visitors who went ahead.

Former Lincoln City midfielder HAND was the man to break the deadlock, picking the ball up 25 yards out and unleashing a stunning shot that beat Arthur and hit the post before dropping into the net.

After conceding their first goal of the season, the Mariners now had it all to do against a side they had been heavy favourites to beat convincingly.

Town were still playing too many long, high balls without any success, gifting possession to their visitors and leading to frustration in the stands and no doubt, on the bench as well.

A better move for the Mariners came down the left on 27 minutes, when good play by Ridley and Eagle led to Coulson getting a low shot in from 12 yards, which was saved by the feet of Harrison.

Hayes and Yeading had seemed to grow in confidence after their goal and they looked to attack at every opportunity, causing problems for the home defence on several occasions.

A shot from Wright took a deflection and looped over the bar for a corner but the visitors could not take advantage from the set piece.

A foul on Eagle gave Town a free kick, 25 yards out and left of centre. Eagle's chip to the far post found Kempson but his header was misdirected. Grimsby retained possession on the right and Bore's header from an Eagle cross had to be tipped over for a corner.

The hosts were now piling on the pressure and Watt was inches away from connecting with a header from another flag-kick, this time from Coulson on the left.

Soon afterwards, Ahmed Deen was shown the first yellow card of the game for a foul on Leary, close to the left corner of the 18-yard box. Connell shot from the free kick but his effort curled over the bar.

Centre-back Charlie Wassmer followed his team-mate into referee Mr Khatib's notebook on 41 minutes for a foul on Coulson out on the right.

The ex-Barnsley forward struggled to recover from the knock he picked up in the challenge and he limped off in the dying seconds of the half, to be replaced by debutant Ademeno.

One added minute was played at the end of a first half that had been relatively short on entertainment from a home point of view.

The Mariners had struggled to impose themselves on the game as the direct approach did not seem to be working, although there had been flashes of potential when the ball hhad been kept on the ground.

The visitors would have been delighted with their 45 minutes' work though, comfortably soaking up most of what Grimsby had thrown at them and heading into the dressing rooms with the lead, through Hand's wonder strike.

No further changes were made by either manager at the break and it was the away side who had the first opportunity of the second half after indecision at the back between Kempson and Watt let Holmes in but his shot was deflected away for a corner.

Ademeno linked up with Bore to create the first opportunity for Town after the restart but Connell failed to connect with Bore's low cross inside the box.

Then, Ademeno found Eagle on the left but his cross was collected by Harrison ahead of Bore.

Town were awarded a free kick when Eagle was fouled on the left and his delivery was met by the head of Connell before it was cleared for a corner. From the flag, a powerful header by Watt bounced up and hit the bar.

Grimsby had started the second half much more positively, looking to build up play patiently and keeping the ball on the deck whenever possible.

The away side were finding it harder to create chances of their own and were instead, relying on defensive errors, with Deen taking advantage after Town lost possession to fire well over the bar from 20 yards.

Another good opportunity came the Mariners' way just before the hour, when good play by Ademeno opened up the Hayes and Yeading defence but when the striker squared for Eagle, he side-footed wide with his right foot.

Micky Cummins replaced Leary in the heart of the Town midfield before a speculative 35-yard first-time shot by Bradley Pritchard briefly had Arthur panicking until the ball skipped wide.

A Town corner from the left almost produced an equaliser when Connell headed towards goal but keeper Harrison got fingertips to the ball and pushed it over the bar.

Hudson went down holding his knee on 67 minutes after a strong challenge by Wright, who was booked for the foul. The midfielder was passed fit to continue but the resulting free kick came to nothing.

Grimsby had been knocking on the door but when the second goal came, it was the unfancied visitors who doubled their lead and left the Mariners staring down the barrel of a first defeat of the season.

PRITCHARD latched onto a through-ball and kept his nerve inside the box, steering a low shot past Arthur and into the far corner of the net in front of the sparse band of travelling supporters from London.

Town boss Woods' response was to send on an extra striker in the shape of Tom Corner in place of Samuels as the Mariners reverted to three at the back.

The youngster nearly made an immediate impact when he was put through by Ademeno, only to see a low shot blocked by Harrison from inside the penalty area.

A foul on Ademeno gave Town a free kick just outside the box and from Eagle's far-post delivery, Kempson rose highest to head the ball into the back of the net but the offside flag had already been raised and the goal was disallowed.

Hudson was well off-target with a 30-yard shot that sailed harmlessly over the bar as Grimsby struggled to find themselves a lifeline with 10 minutes to go.

Town did eventually find the net in stoppage time, when CONNELL turned and shot over Harrison into the top of the net.

From then on, it was a frantic finale as the Mariners tried in vain to snatch an unlikely point, with Cummins heading their best opportunity over the bar.

But as the referee's final whistle blew, it was the 27 visiting supporters who celebrated their side's victory, leaving Grimsby to reflect on what might have been.

Town are next in action on Tuesday evening, when they travel to Darlington.