The U’s made two changes to their starting eleven, with Magnus Okuonghae missing out with a hamstring injury and Alex Gilbey suspended – Frankie Kent and Sanchez Watt stepping into the team.
Tony Humes' men managed to pull one back as Sears made amends for his penalty miss with a far post conversion from Macauley Bonne's header, but time was the U's enemy in the end as Vale took the points.
In their last four matches, they had come from behind to earn eight points but, after Freddie Sears missed a first half penalty, they saw Vale take a two goal advantage.
It was one comeback too far for Colchester United on Saturday, as they fell to a 2-1 defeat against Port Vale.
The home side started on the front foot and had half a sight of goal after eight minutes, when the ball was fed through to Sears, but it wouldn’t sit down in time for him to get his shot away.
They went close again on fourteen minutes as a swift one touch passing move from right to left ended with the ball finding Sears in the box and he sidefooted inches wide.
Vale weren’t out of the game, though, and first Clohessy blocked bravely as the goal opened up for the visitors, before a second chance was fired wildly over the bar by Birchall.
It looked like Vale might take the lead when they outnumbered the U’s on the counter and, when Williamson drove in a low shot, it was a fine reaction save from Walker.
At the other end, Massey sized up a shot which he curled towards the bottom corner, forcing a good stop out of Neal in the Vale goal.
The chances kept coming and next Marshall went up against Clohessy, with the U’s full back getting into position to turn the winger’s cross-cum-shot onto the post.
The U’s had the ball in the back of the net on the half hour mark from another swift counter attack, but the flag was up before Healey slotted home. Had he left it for the onrushing Sears, he may well have scored.
The U’s top scorer should have put the home side ahead on 32 minutes as Massey was felled in the box, but Neal guessed the right way to save Sears’ penalty to keep the scores level.
Then, at the other end, Vale had the ball in the net from a corner as Walker came out to collect, but the referee adjudged he had been fouled by McGivern as he caught the ball.
Level at the break, the U’s got the first sight of goal six minutes into the second half, as Watt burst into life and slid in Healey. He looked destined to get a shot in but Duffy blocked well.
The U’s had their tails up and Moncur forced a low save out of Neal, but the visitors got their noses in front eleven minutes after the interval.
The ball found Marshall in space at the far post, and he had time to set himself before drilling home a low shot past Walker.
And they went further behind two minutes later. Again it was a ball to the far post and this time it was substitute Daniel, who had just come on, who fired home in similar fashion to the opener.
The U’s introduced Bonne and Szmodics halfway through the second period, and the home side were almost thrown a lifeline with nineteen minutes remaining.
Moncur’s free kick was parried by Neal but no U’s player could follow up and, from a follow up corner, Massey’s shot on the turn cannoned off the top of the upright.
They did manage to set up a grandstand finale when they got one back with ten minutes to go. Watt drifted a cross to the far post that Bonne nodded back across goal. It may have been creeping in,b ut Sears made sure it crossed the line with his ninth of the season.
In the end, though, time ran out and the U's fell to a first defeat in five.
Whilst the U’s never truly got a head of steam going in those latter stages, they had another chance as Watt turned in the area, but fine defending from Vale denied him.