The Foxes were denied a deserved point when they were sunk by a goal three minutes from time.
Just seven days before, the Foxes had lost 5-0 to the same opponents and could have been excused for expecting another beating. But the hosts produced a totally committed performance which looked likely to reap rewards.
In an even opening the visitors looked dangerous with their tricky wide players troubling full-backs Jacob Bates and Ben Wilkinson.
The Foxes went close when Shaun Smith was put clear, but sliced his shot wide from six yards.
With much of the play confined to midfield, the visitors took a surprise lead after Melton gave the ball away in midfield. Foxes thought they had cleared the danger until an Allexton winger chested the ball down and sent a dipping 25-yard volley past Thorn.
From the restart, Smith turned and hit a powerful drive goalwards which the keeper failed to hold, allowing it to roll over the line, but the referee did not award the goal.
Smith again went close before the hosts deservedly equalised in the 23rd minute. Winger Kenny Jones swung over a cross which found Smith who quickly turned the ball across goal where Alex Walker forced it home.
Play remained even after half-time with Melton’s full-backs keeping the visitors wide men quiet.
Bradley Carroll charged down a clearance by the keeper, but Jones put the loose ball on top of the net with the keeper stranded.
Keeper Thorn had to push a 20-yard drive round the post before Thorpe collected a loose ball at the other end and fired inches wide.
Thorn made an incredible save, leaping to his left to turn a goalbound shot from the edge of the box over, but with full-time looming the Foxes failed to clear, and the Allexton striker’s low shot went in off the post.
Foxes: J. Thorn, J. Bates, J. Nickolls, G. Wilkinson, B. Wilkinson, A. Walker, L. Thorpe, C. Lovegrove, S. Smith, C. Steans, B. Carroll, C. Beeken, T. Hope.