Pools were second best throughout the contest as a hat-trick from Danny Johnson contributed towards a comfortable afternoon for the Saddlers.
Bradnon Comley’s deflected strike gave the hosts the lead midway through the first half before former Gateshead man Johnson doubled the lead five minutes later.
And Johnson added an excellent third on the hour, powering beyond Ben Killip.
The striker, on loan from Mansfield Town, completed his hat-trick in the second half when converting from close range to condemn Hartley to a miserable opening day defeat.
Pools might have been on the end of an even bigger defeat but for a number of saves from Killip with Hartley left with plenty to ponder.
After a decade of management in Scotland, Hartley made the decision to move to England and test himself in the Football League having been appointed as Graeme Lee’s successor in the summer.
But it’s fair to say both teams were stepping somewhat into the unknown at the Poundland Bescot Stadium with Pools naming no fewer than eight debutants in their starting XI, and hosts Walsall naming seven themselves.
Of those eight to be handed a first start by Hartley included centre-back pairing Alex Lacey and Euan Murray - the Scotsman passed fit following his 45 minute return from a hamstring injury against Sunderland.
Reghan Tumilty got the nod over Jamie Sterry at full-back after the former Newcastle United man has struggled with injury throughout pre-season.
Callum Cooke and Mouhamed Niang joined Nicky Featherstone in midfield while there was a new-look front three in ex-Rangers winger Jake Hastie, Hartlepool’s own Ellis Taylor and striker Josh Umerah who joined for an undisclosed fee from Wealdstone.
But after a fairly even opening it was the home side who began to dictate things with the lively Taylor Allen bringing a good point blank stop out of Killip.
The goal did come for the hosts though after a quick corner routine from Isaac Hutchinson and Allen was eventually cleared to Comley on the edge of the area. His strike went through a crowd of bodies before deflecting beyond Killip.
The Saddlers were really in the ascendancy at that stage and a swift counter-attack led to a second five minutes later.
Hutchinson was allowed to advance through the centre of the field from his own half before laying it into Johnson who powered at Killip.
And when his first effort was saved, Johnson found the ball back at his feet and made no mistake the second time of asking.
It already seemed a long way back for Pools who barely tested Owen Evans in the home goal with Umerah’s dragged effort the best they could muster in the first half.
Things weren’t to change after the break as Walsall added a third through Johson on the hour.
Cooke was dispossessed on the wing as Hutchinson scurried away down the left and his cross found Johnson who finished with real class beyond Killip to seal the contest.
But the home side, and Johnson, weren’t done as 18 minutes from time Johnson added his third
A deep free-kick found the head of Manny Monthe who nodded back across goal to Johnson who was on hand to easily find the net.
Substitute Douglas James-Taylor came close to adding a fifth for the Saddlers only for Killip to get down well to his left with Hutchinson also bringing a smart stop from the Pools No.1.
Hastie and Jack Hamilton were denied late in the day for Pools with Umerah also going close as Hartley’s side were left to reflect on a disappointing afternoon in the Midlands.