Michael Gash's second-half winner fired Kidderminster Harriers back to the top of the Blue Square Bet Premier with victory at Wrexham.
Mansfield's earlier defeat at Braintree gave Steve Burr's men the chance to hit the top again and they took advantage.
James Vincent gave them a 19th-minute lead, a bobbling shot through a crowded area before Danny Wright replied with a spectacular 62nd-minute volley.
But Gash then won it for the Harriers, lobbing stranded keeper Chris Maxwell.
Wrexham were only back on level terms for nine minutes before Harriers left-back Mickey Demetriou sent Gash racing clear to delicately convert his first goal in five games.
Gash had also been involved in the Harriers' first goal, his free-kick hitting the wall before dropping for Vincent, whose effort snuck through the mass of bodies and into the far corner - only his third goal of the campaign.
It was a first home defeat since November for Wrexham, who secured their play-off spot in midweek.
But, although second-placed Mansfield still have a game in hand - at Hereford United on Tuesday night - the Harriers have put themselves in a strong position to take advantage of any further Stags slip-ups.
Wrexham also play in midweek, at home to Braintree on Tuesday night, before having a further say in the title race when they go to Mansfield next Saturday,
VIEW FROM THE DRESSING ROOM
Wrexham player-manager Andy Morrell told BBC Radio Wales:
"Two mistakes on our part have given them two goals. I thought it was fairly equal but, in this league, when you make a mistake, you get punished for it.
"Of the starting XI ,we've had six come through our centre of excellence and had two more on the bench as well that got on.
"That's a great sign for the future. All of them equipped themselves really well.
"I'd still back us over two legs against anybody in the league. We'll give any team a game when we get our bodies back."
Kidderminster Harriers assistant manager Gary Whild told BBC Hereford & Worcester:
"Obviously Mansfield losing was a lift for us. But we just had to concentrate on what we had to do and to try and keep doing what we have for a long while now.
"It's a difficult place to come and they're a good side, but the way we handled the game from start to finish was superb and I thought we thoroughly deserved it.
"We picked ourselves up and came back after losing the lead to a strike that was out of this world.
"The character came to the fore again, as it has done all season and, to be fair, it was also a fantastic finish from Michael Gash."