King's Lynn manager Gary Setchell is taking nothing for granted as his team go into their final home game of the season tomorrow, knowing that victory over Sheffield will end three years of frustration by sealing the Evo-Stik NPL Division One title.

While former runaway league leaders Coalville were continuing their nightmare run-in – squandering more points in a 1-1 draw at Rainworth Miners Welfare – the Linnets did what they needed to do to take full advantage.

Steve Spriggs converted a 73rd minute penalty after Sam Mulready had been brought down while ghosting his way between two defenders to claim his 27th goal of the season and open a four-point advantage with just two games to go.

While the Linnets host the world's oldest football club tomorrow, Coalville travel to Leek. On Saturday Setchell's men finish their programme at Belper – who could yet pip Coalville to second place – while their title rivals host another team in play-off contention, Chasetown.

But the Lynn boss is adamant: 'We looking to get it wrapped up as soon as possible. The odds are now very much in our favour but we wouldn't be the first team to lose a league title from this position.

'We know there's still a job to be done and we're taking nothing for granted, especially as we're facing a very good Sheffield team who beat us 2-0 earlier in the season. Having said that, we've improved a lot since then.

'We've some experienced heads who know how to see a game out and four or five players who can win matches from nothing.'

Both of those factors came into play at Greenfields, where the home side had much the better of the first half, though Dan Quigley and Phil Gulliver both had shots saved.

It was a different story after the break. Having dug in to be level at the interval the Linnets took control even before a bold switch by Setchell – bringing on Mulready and Russell Dunkley for Danny Beaumont and Shane Tolley – led to the breakthrough.

The winner came when a long goal-kick from Danny Gay was flicked on by Dunkley into the path of Mulready, who was brought down in the box.

'It could have been two penalties,' joked Setchell. 'Because we felt he was clipped as he first brought the ball down. But it was a brilliant piece of skill.'

One worry for Setchell was the sight of Quigley being carried off with a foot injury. He's rated doubtful for tomorrow's game.

• Market Drayton: Lloyd-Weston, Porter, Swetnam, Johnson, Mayo, Blake, Stevenson, Fox, Thomson, Davies, Proffitt.

• King's Lynn Town: Gay, Watson, Yong, Lee, Gulliver, Thomson, Spriggs, Quigley (Fryatt 58), Beaumont (Dunkley 63), Tolley (Mulready 63), Jacob. Unused sub: Butt, Jepson. Booked: Watson.

• Attendance: 168