Blackpool failed to build on a strong first-half showing as Colchester United came from behind to win 3-2 at the Weston Homes Community Stadium.
Much the better side in the opening period, Pool led through Armand Gnanduillet, before Sammie Szmodics levelled things up.
After the break the visitors lost their defensive shape and Chris Porter made them pay with two simple finishes from close range.
It made it a long return back to Lancashire for The Seasiders, who pulled one back late on through Brad Potts’ free-kick but it wasn’t enough.
Blackpool had started on the front foot in Essex and after a series of probing attacks, Kyle Vassell volleyed at Sam Walker four minutes in.
Colchester’s first sight of goal came through the small frame of Szmodics, but the midfielder’s shot flew wide of Sam Slocombe’s right-hand post.
It was brilliant link-up play from Pool’s front two which set up the opening goal. Vassell showed terrific chest control before lofting a ball over the top for Gnanduillet, who shrugged off his man and fired high into the net.
The big man was proving a real thorn in Colchester’s side and tested Walker soon after.
Gary Bowyer’s men were dominating proceedings and looking a real threat going forward, so will have been disappointing to see Potts’ effort nestle into the side netting.
The home side’s chances were few and far between at this point, and even when Szmodics prodded wide, the linesman’s flag had Pool covered.
However, the midfielder was Colchester’s main threat and when they equalised against the run of play, it inevitably came through him, as he turned home following an unfortunate slip from Kelvin Mellor.
Blackpool responded well but Tom Aldred couldn’t divert his header on target after meeting Danny Pugh’s corner just moments before the half-time whistle.
Half-Time: Colchester 1 Blackpool 1
After the break the home side improved and Slocombe had to turn over a powerful strike from Drey Wright in unorthodox fashion.
Andy Taylor’s wastefulness in possession gifted them their next opening, but thankfully Kurtis Guthrie nodded wide from Szmodics’ cross.
They were getting closer, next Guthrie’s header was turned over one-handed by Slocombe. However, untidy defending eventually led to the home side taking the lead, as Porter turned into an open net.
Bright Osayi-Samuel was then brought off the bench in place of Colin Daniel – a change which was planned before Porter’s strike.
Blackpool settled from that point and both Potts and Aldred needed to fine-tune their radars after wayward efforts.
After the hour-mark the game became stretched. First Vassell’s endeavour and industry set up Potts, whose header was kept out by Walker, before Slocombe denied Tarique Fosu.
With ten minutes remaining Vassell and Jim McAlister made way for the returning Danny Philliskirk and Jack Payne.
However, after Blackpool penalty appeals fell on deaf ears following a clear handball, United sealed victory as Porter turned Clark Robertson inside the penalty area and slotted beyond Slocombe.
Potts did at least make things interesting when his powerful free-kick squeezed past Walker. There would be one final chance to claim a point too, but Aldred headed over from Payne’s corner.
Full-Time: Colchester 3 Blackpool 2