Tom Pope’s two goals and an assist condemned the Shrimps to their fourth home league loss of the season.
The striker netted in each half and then created Cristian Montano’s stoppage-time goal as Jim Bentley’s players paid the price for another poor Globe Arena performance.
Bentley had made just the one change from the side which claimed three points at Chesterfield last time out with Rhys Turner coming in for Aaron Wildig.
However, his involvement ended with half-time three minutes away after suffering a hamstring injury when chasing a ball forward.
The long ball was Morecambe’s principal first-half attacking tactic against a Vale team playing with a high defensive line.
Unfortunately from the home perspective, it singularly failed to pose any kind of serious threat to the visitors despite a decent enough opening quarter-hour.
Yet, ironically, when they did try to get the ball down and pass it, they went behind on 18 minutes.
Rather than clear his lines, Max Muller lost possession on the edge of his area, Aaron McGowan failed to prevent Ben Whitfield from crossing and Pope headed home from six yards.
The striker could have netted again moments later but saw a shot blocked and a header comfortably held by Barry Roche.
At the other end, the Shrimps - try as they did - were unable to force Vale keeper Kelle Roos into action.
One long throw was worked back to Andy Fleming, who dragged a shot wide, while Alex Kenyon was similarly off target from 25 yards.
That was pretty much that from the home perspective before the break as Tyler Denton lobbed over Roche’s goal and the keeper pushed out David Worrall’s fierce effort.
Worrall was denied by the woodwork early in the second half and Marcus Harness screwed a shot horribly wide after Turner’s replacement, Adam Campbell, lost possession.
Tom Anderson headed into the side netting and Roche pushed behind Whitfield’s shot before Vale doubled their lead midway through the half.
The ball was somehow allowed to reach Pope, who then shrugged off some indifferent challenges before bundling home his second.
Morecambe came within inches of halving their deficit with 20 minutes left when Garry Thompson’s shot struck Roos and rebounded onto the bar but that was as good as it got.
Roche kept out another Harness shot before a final dose of salt was added to the Shrimps’ wounds in stoppage time.
Pope capitalised on some indifferent defending before cutting the ball back for Montano to wrap up the scoring and a deserved three points.
Morecambe: Roche, McGowan, Muller (Rose 56), Old, Conlan, Kenyon, Fleming (Osborne 84), Thompson, McGurk, R Turner (Campbell 42), Oliver. Subs not used: Nizic, Wildig, Lavelle, Lund.
Port Vale: Roos, Gibbons, Anderson, Smith, Gunning, Pugh, Worrall, Whitfield (Barnett 84), Harness (Montano 89), Denton (Tonge 46), Pope. Subs not used: Boot, Davis, Kay, D Turner.
Referee: Ross Joyce.