Vale, who had lost the previous two games, made four changes going into this one following the poor showing in the week against Walsall.
Despite it being a game of few chances, Darrell Clarke's outfit put in a solid defensive performance helped with clinical finishing up top to see them through as the Pool failed to accumulate a single shot on target.
This result sees the Valiants remain in fifth, only two points adrift of the automatic promotion spots, while Hartlepool sinks to a fifth successive defeat that sees them slip down to 17th.
Story of the game
After an even start to the affair, it was the hosts that registered the first shot on goal just before the tenth-minute mark when Garrity went on a bursting run through the middle and squared the ball to David Worrall.
However, his first-time effort from the right was blazed well over the crossbar.
As the half wore on it was Hartlepool that were looking the more threatening and were pinning the Valiants deep inside their own half without carving out a chance of any real meaning.
Inside 29 minutes on a rare attack, Vale countered and James Gibbons delivered a good cross from the left that narrowly evaded the leap of Worrall at the back post.
This seemed to spur Clarke's men on as only two minutes later his side broke the deadlock through Garrity's fourth goal of the campaign.
Amoo was played down the right-hand channel and managed to slide the ball across the face of goal into the arriving Garrity who under pressure from point-blank range stumbled the ball home.
The opener appeared to provide Vale with much more of a boost as they started to play with much more energy and seven minutes later, they forced Ben Killip into a save when Worrall was found on the right by Devante Rodney, but his low drive was held by the 26-year-old.
After the break, the game continued in the same fashion with neither side able to gain a grasp and control the game.
The first real opening of the period came in the 68th minute when after good build-up play down the left-hand side, Tom Pett was found in space inside the area, but he snatched at his volley as it was fired over the top.
With the clash still lacking energy, Anthony Sweeney's side were close to getting a leveller out of nothing on the 78th-minute mark when a cutback from the left ricocheted its way through to Luke Hendrie, but he failed to control the ball and Lucas Colovan was quick to collect.
Three minutes later, Amoo got down the right and flashed an effort on goal that arrowed wide, moments before Gibbons was found in room in behind but his drive was well blocked by Killip.
As the game was livening up, Hartlepool went up the other end and would have felt they should have done better when substitute Will Goodwin was slipped inside the box.
Despite rounding the keeper, the angle was too tight for him to guide the ball home as he failed to find the target.
With only five minutes to go, Killip made another decent stop to keep out Garrity's strike inside the area, after he was found by Rodney on the left.
However, the three points were all wrapped up in the 90th minute when Pett went on a mazy run down the right and when in space, his shot found its way past Hartlepool's number one and into the bottom right-hand corner.
Solid defensive performance huge factor for three points.
Going into the game, Clarke made two defensive changes as Dan Jones dropped to the bench and Nathan Smith didn’t make the matchday squad with former Hartlepool man Ryan Johnson and Aaron Martin joining Lewis Cass to make up the back three.
With a slightly rotated defence being fielded, there may have been the concern that Vale will be exposed due to the lack of playing time the trio have played together for the club.
However, in reality, this was not the case as Clarke’s back three were defensively organised, strong and made sure that they dealt with any danger that came their way.
The visitors really struggled to find a way in behind Vale’s defence with the pace that Cass possesses helping him to make up the ground on many occasions to great effect.
The Newcastle United loanee when in space wasn’t afraid to carry the ball and venture forward, making Hartlepool drop their defensive line deeper creating space in dangerous wide areas for the likes of Worrall.
The solid showings of the two defenders that were brought in for today’s game will be a sign of encouragement for Clarke as it showcases the quality that can come in when the team do have absentees, or when some players aren’t performing up to the standard that the manager expects.
Star Player- David Worrall
The 31-year old put in a performance that fans are used to seeing down Vale Park with it seeming him being quite reserved over the last couple of games.
Despite playing at right wing-back, he was trying to get forward as much as possible and was causing a problem down that channel for left-back Eddy Jones.
It was a showing that Clarke will be wanting to continue seeing on a consistent basis as everyone knows the quality he possesses and it is this along with him staying fit that is what will be vital if the Valiants hope to form a promotion charge come the end of the season.