The North-East side are now unbeaten in 15 games and are clearly the ones everybody in League Two has to fear after winning at Swindon a week earlier.
But it was never plain sailing. Walsall took the lead before either side had really got used to the strong wind blowing across the pitch, jumping ahead in the third minute.
A corner was only half cleared by the home defence, and when it was returned to the penalty area, Martin Butler was unmarked on the right. And with Hartlepool appealing for offside, he controlled it well and drilled a low shot into the bottom corner from 15 yards.
The home team battled to recover from the shock, but struggled to create chances until the 21st minute, when a weak Walsall clearance landed at the feet of Richie Barker on the edge of the area. But his shot was well saved by Clayton Ince, diving to his right.
On the half-hour there was a massive scramble in the Walsall area as Hartlepool had a string of shots blocked by a packed defence. And, just before the break, Eifion Williams tried a shot from more than 30 yards which was just off target as the first half ended with Hartlepool piling on the pressure.
The pressure stayed on after the break, too, and it took the home team just seven minutes of the second half to level with defender Michael Nelson powering in a great header from a corner.
Hartlepool stayed on top for the remainder of the game, but struggled to find a way through - until that dramatic late finish.
Two minutes from the end a free-kick 25 yards out and right in front of goal was taken short for Richie Humphreys to curl a great shot round the wall and just inside the right-hand post of diving keeper Ince.
And it was not over yet for the delighted home crowd, striker Richie Barker stabbing home a third in the last minute after a great run by Antony Sweeney.