This was a massive game for both sides. Darlington still require every point going in their quest to escape the bottom reaches of the League, whilst for promotion hopefuls Town the three points were a must.
But Darlington began the brightest in the game and the visitors were kept on the back foot in the opening 20 minutes of the game.
In that period, the home side had struck the woodwork three times as Kevin Pilkington's goal led a charmed life.
In only the third minute of the game, Darlington gained a corner and when Mark Convery's cross found the head of striker Barry Conlon a goal looked to be on the cards, but somehow Pilkington finger-tipped the ball over the crossbar for another corner.
When the kick again came across, Conlon again rose highest but failed to find the target as the ball went inches wide.
The visitors appeared shell-shocked as the hosts ran riot and in the seventh minute on-loan striker Danny Graham fired against an upright and then seconds later, in Darlington's next attack, Graham broke free inside the area, fired across goal and saw his effort strike the opposite post.
The visitors began to find some rhythm and Wayne Corden saw his 20-yard drive tipped over the bar by Darlington keeper Michael Price in the 14th minute.
But Darlington came back again and Conlon headed against the crossbar in the 20th minute. As the game went from end-to-end Price took up a good position to deny Junior Mendes.
As the first half wore on the Stags took control and they finished the half strongly. In the 35th minute, Colin Larkin headed a Liam Lawrence cross against the post and then Corden fired wide in the 42nd minute.
A minute later Lee Williamson shot straight at Price and then in time added on Lawrence fired narrowly wide.
Darlington grabbed the winner in the 49th minute when Convery's corner was only half cleared and defender Matt Clarke headed in the loose ball.
The visitors couldn't find an equaliser although defender Rhys Day headed over the bar from close range in the 58th minute.