The patched-up Linnets pulled off a heroic upset to dump Conference North Hednesford out of the FA Cup thanks to George Thomson's 82nd-minute penalty.

Despite missing four key men, the hosts ran their socks off to stay in the game and clinch their winner when Jake Jones was shoved over in the box by Alex Melbourne with little more than 10 minutes to go. Thomson made no mistake as Dan Crane – who made great saves to deny inspirational centre-back Ross Watson and Michael Frew – was finally beaten.

The miraculous triumph is perhaps one of the new club's greatest cup giantkillings, and they've had a few, as they progressed to the third qualifying round and pocketed £4,500 prize money in the process. And it was the least they deserved for a performance that was full of grit, determination, heart and everything else you've come to expect from a side managed by Gary Setchell.

Lynn's boss – without Jackson Ramm (suspended), Henry Eze (cup tied), David Bridges (family wedding) and Dan Quigley (injured) – was handed a massive boost prior to his side's second game in this season's competition. Watson and Sam Mulready were fit enough to start after being rated as 50/50 going into the weekend.

The duo's inclusion was enough to turn Lynn's near-impossible task into a slightly less, but still very, difficult one against the Pitmen who sit mid-table in their division which is a tier above the Linnets. That said, Setchell was still forced to name four reserve-team youngsters in his squad with Tom McLeish, Jack Frohawk, Eoin McQuaid and keeper Luke Pearson filling the large void left by the missing quartet.

With the odds stacked against them, the hosts knew they had to start well. And that's exactly what they did as Frew's inventive effort flashed just wide with the help of a deflection. A flurry of early corners helped put the visitors under pressure. Yet they eased into the fixture and a couple of blocks from Watson and fringe player Shaun Stocker, being played at right-back, showed the men in blue were starting to get into good areas.

Marvin Robinson stung the palms of home keeper Alex Street with a fierce shot and Lynn's number one was thankful for the offside flag as Danny Glover's excellent rebound from a tight angle was ruled out for offside.

The Linnets carved open their best chance on the quarter-of-an-hour as Stocker played in his skipper David Bell. The former Norwich City midfielder's trickery saw him round goalie Crane out wide and stand up a great ball at the back post for frontman Mulready. However, his header – despite big appeals from the striker and team-mate Jones – was deemed to have been blocked in front of the goal-line by centre-back Francino Francis as Crane rushed back to regain his position between the posts.

The goal-saving intervention was enough to end Francis' afternoon as he limped off to be replaced by Paul McCone. But the opportunity was enough to inject even more confidence into the veins of those wearing the blue and gold as they hustled, harried and pressured at every opportunity.

The home faithful thought they'd seen their heroes take a deserved lead when Watson powerfully headed a Bell set piece towards the top right-hand corner of the goal. But somehow, incredibly, Crane clawed the ball to safety even though it looked destined to fly past him and into the net. At the other end, Glover whistled a drive wide as he continued to look dangerous.

It didn't rock the Linnets mind who would have taken the lead a few minutes later – had it not been for more heroics from the man with the gloves on. Bell's set piece was bulleted towards the target by Frew's head but Crane rose off the deck to majestically palm the ball away. It was his second stunning moment, perhaps not as impressive as his first, but equally instinctive.

His opposite number Street produced a smart piece of work to not spill Glover's third effort on target. But Lynn in truth were doing well to restrict the Conference outfit to just pot-shots and half chances.

For the remainder of the half the home side continued that effort and endeavour, coupled with quality when they got the ball, that had served them so well right up until the break as an enthralling half at an unusually noisy Walks came to a close.

The second period started with more appeals from the home faithful as Melbourne upended Mulready as he went to latch onto a through ball. While they claimed he was the last man, the defender was probably about 30 yards from goal and was only booked by referee Neil Hair.

More frustration at the whistle-blower continued as Hednesford created a chance, despite Watson was shoved in the build-up, only for Jamie Ashmore to screw way off target. A good covering header from Jordan Yong denied Tom Thorley a clear sighter at the back stick as the Linnets tried to settle themselves again.

Yet the away side started to turn the screw and Ben Bailey tested Street with James Hurst lashing into the terracing behind the goal as the ball found him on the edge of the box.

Jones had an incredible chance to relieve some of the pressure when he robbed substitute Archie Love and created a remarkable five-on-two situation. Yet, to the dismay of the home supporters, he picked the wrong pass and stopped the momentum.

Ryan Fryatt spilled blood, again, courtesy of a clash of heads and was replaced by Chris Ward at the heart of the Linnets' defence with about 25 minutes to go. The new arrival was beaten too easily by James Osborne with 15 to go and while his cut-back from the by-line found Glover, his shot was cleared by the boot of Street. The Hednesford number nine curled a free-kick inches past the upright as the Staffordshire outfit search for a winner. Tom Peers lashed a hopeful half-volley wide. But the away side continued to look the likelier to find a winner as the game wore.

And that elusive strike finally came when Melbourne shoved Jones over and Thomson buried his spot-kick. Some late clearances by the rock-solid Watson and great catches from Street saw Lynn over the line and ensured their name was in Monday's draw.

Lynn (4-4-2): Street, Stocker, Watson, Fryatt (Ward, 66), Yong, Spriggs (Frohawk, 88), Bell, Thomson, Jones, Mulready, Frew. Subs not used: McLeish, McQuaid, Pearson. Booked: Jones. Goal: Thomson (pen, 82).

Hednesford (4-4-2): Crane, Hurst, Campion, Bailey, Francis (McCone, 20), Ashmore (Love, 62), Osborne, Melbourne, Glover, Robinson (Peers, 76), Thorley. Subs not used: Peers, Taylor, Westwood. Booked: Thorley, Hurst, Melbourne. Goal: None.

Referee: N. Hair

Attendance: 556