King's Lynn pulled off a famous victory at The Walks to advance to the first round proper of the FA Trophy.

Second-half goals by Russell Dunkley, Steve Spriggs and Sam Mulready put Lynn through to Monday's draw, at the expense of a side who play their football two levels higher than the Linnets, in Conference South.

It was tough going in the first half, but Lynn defended resolutely – and then turned on the after burners as the game progressed, turning a fine defensive performance into a fine attacking performance.

Manager Gary Setchell was forced into changes – keeper Danny Gay and midfielder Pat Bexfield were both cup tied while centre half Jason Lee was at a wedding.

After only two minutes Lynn were given an eye-opener, when Gary Hart timed his run to perfection to beat the offside trap, but shot wide of Street's right-hand post – an early let-off.

A testing ball into the area by Russell Dunkley almost fell for Steve Spriggs, but Borough cleared as the hosts enjoyed the lions' share of the early possession.

Marvin Hamilton put a free-kick into the Lynn wall after Quigley fouled Hart, with Borough seeing more of the ball as the 15-minute mark approached. Street then came and flapped at a couple of balls into the box and was fortunate to see Adam Watts shoot inches wide of his left post.

There was little between the teams, although the visitors looked more threatening – although on 21 minutes Dunkley did well to make space in the area to turn and shoot, although keeper Nick Jordan was right behind the shot.

The crowd's reaction when Street caught a poor free-kick by the visitors perhaps reflected the team's anxiety, and Borough almost benefited when two more corners caused consternation in the home box.

Borough striker Hart was lucky to get away with a talking-to by referee Dudley, after kicking out at Ross Watson.

Kez Ibe then worked some magic on the Borough right, curling a left-footer that crashed back off Street's bar, with Watson brilliantly tackling Frankie Raymond to deny him the follow-up.

Danny Beaumont showed for the first time when he almost cashed in on a Dunkley reverse pass, but keeper Jordan just got to the ball first.

Hamilton beat Watson all ends up, slipped it into Ibe, whose shot was deflected for a corner, with Watts finally shooting high and wide to relieve the pressure for Lynn.

It was hard going for Lynn, who were forced into a change just before the break when Jason Turner replaced Beaumont, who had failed to shake off a knock. Lynn needed a half-time pep talk - the question for Setchell would be how to make them look more assertive against a side which ended the half showing their higher league standing.

Turner did well to block Ben Adelsbury's shot after a quick Borough break,

Watson then produced a superb tackle in the area to deny Hart as he bore down on goal. A corner at the other end soon followed and the crowd responded – perhaps the pick-me-up Lynn needed.

Watson spotted a great run by Spriggs down the right but the winger's low cross was just a foot in front of Turner – it was the first the crowd had seen of Lynn for a while.

But danger always lurked and Hamilton then found space at the back post to head goalwards, Street palming it away for a corner.

Then came the breakthrough - Watson and Spriggs played an excellent one-two on the right; Watson advanced into the area, but looked to have lost the shooting opportunity. But instead of wasting valuable possession, he squared it across the face of goal, and there was Dunkley to turn it in from close range.

It was great reward for the Watson-Spriggs combo, which had been excellent all afternoon.

The Walks crowd responded, knowing that a second goal could be too much for the visitors. The decision was, perhaps, whether to stick or twist.

Turner could have settled the argument on 72 minutes, but missed the target with a simple header after good work by Dunkley, but Lynn were on top, and the crowd were in good voice.

Turner then saw keeper Jordan smother a shot after more good work by Dunkley, as Setchell called on his players to lift themselves for one last effort.

Spriggs was set up for a shot by Dunkley, but scuffed his effort. But with the clock running down, Lynn were on top.

Hart had Borough's best chance of the half so far, heading Raymond's cross over – but within a minute Lynn were 2-0 up. Spriggs was the scorer, slotting past the keeper, but it was Scott Quigley who was the architect, taking a quick free-kick which left the winger one-on-one.

Lynn had time to add a third in time added on, sub Sam Mulready heading home Jamie Thurlbourne's cross.

• Lynn: Street, Watson, Gulliver, Fryatt, Yong, Spriggs (Mulready 88), Bunting, Quigley, Thurlbourne, Beaumont (Turner 44), Dunkley.

Subs: Buhlemann, McLeish.

Goal: Dunkley 64, Spriggs 85, Mulready 90

• Eastbourne: Jordan, Watts, Cole, Adelsbury, Rowe, Uddin, Johnson (Remy 62), Raymond, Hart (Gorman 90), Ibe, Hamilton (Lok 75).

Subs: Knight, Noone.

Booked: Uddin, 77, foul on Turner; Rowe, 82, dissent

• Att: 661