Manager Richard Money heaved a huge sigh of relief after a massive blip in their recent fortunes when they allowed Hartlepool to overtake them at the top of the table.
Recent signings, Harper and Kevin Cooper, made an immediate impact. Harper, on loan from Stoke, marked the game with two well-taken goals to ease the pressure which has been building up at the Bescot.
On the back of three successive defeats Walsall badly needed to regain their winning form but they had to fight hard in a game marked by individual errors.
With only five points from their previous seven games, Walsall were far from confident in their approach, and this was reflected in the 22nd minute when Barnet took a shock lead.
There was no apparent danger when Scott Dann slipped as he was about to clear. Oliver Allen, to his credit, quickly spotted the opening and whipped the ball into the bottom corner of the net.
It was his second goal in successive games and the striker certainly gave the Bees an attacking bite.
The goal set off the alarm bells for Walsall and they were somewhat fortunate to get back into the game.
Newcomer Kevin Cooper marked his arrival on loan from Cardiff by creating the equaliser in the 33rd minute.
He crossed from the right and Barnet skipper Ian Hendon misjudged the centre and sliced the ball into his own net.
It was a life-line for the Saddlers. They lifted their game with Cooper emerging as the major driving force.
Early in the second half Walsall skipper Martin Dobson worked his way through the Bees defence but fired his effort over the bar.
Dobson, however, still had an eye for a goal and to his delight was on the mark in the 55th minute.
Dean Keates floated in a free-kick from the right and Dobson scored with a glancing header for his first goal since his two against Peterborough last September.
The goal opened the door for Walsall as Barnet had to switch their tactics in an attempt to obtain an equaliser.
But Barnet left themselves exposed and this was exploited by Walsall in the 65th minute when Harper took a return pass from Martin Butler to run home an easy goal.
Barnet went close when keeper Clayton Ince fumbled a Nicky Bailey free-kick and Simon King's close-range shot was blocked.
Walsall sealed Barnet's fate in the 77th minute when Harper notched his second goal. Keates' corner was headed back by Anthony Gerrard, and Harper lashed his close-range effort into the net.