Jack Marriott grabbed one back to give the U's late hope, but the clock ran out on the home side as their woes at the Weston Homes Community Stadium continued.
Unfortunately for the U's, that same goal in front of the Roman Cars Stand saw Crewe score three times to turn the game on its head.
After a first half that looked like it might be the precursor to a tight 0-0 draw, Chris Porter broke the deadlock in some style with a lashed effort from the edge of the box.
In the battle of the sides either side of the dotted line at the foot of the League One table, it was Crewe Alexandra who came out on top with a 3-2 victory at the Weston Homes Community Stadium.
Lapslie started alongside Fox again in the midfield after recent impressive performances by the youth player, most notably his performance against Leyton Orient in that emphatic 2-0 home win for the U’s.
Sanchez Watt looked lively as he tested Crewe right back Ray and angled in two low crosses but he couldn’t quite find a blue shirt inside the area to give Colchester lift off in the opening few minutes.
The U’s continued to press and a moment of magic almost put the home side ahead. Gavin Massey brought the ball down superbly and went on a surging run into the box, before shifting his body to get a shot away but Crewe blocked his effort well.
Crewe were failing to get a real grip of the game inside the opening fifteen minutes and were caught asleep after a superb long ball from Fox found its way to Porter in the area, who controlled it well and hit a first time volley but it flew just wide of the post.
Both sides were struggling to create any real clear chances as the battle in midfield began to take shape. Massey broke clear mid-way through the first half and took on Ray but he couldn’t quite find anyone in the box as the frustration grew.
The first half lacked action but Colchester finally had their break through after an incredible strike from Porter where he brought the ball down and rifled a shot left footed past Garratt and into the top corner to give the home side the advantage just before the stroke of half time.
Despite having more of the possession, the away side failed to create any clear cut chances in the first half and found themselves trailing after hesitant defending allowed Porter time and space to get his shot away after a good ball by Wynter.
Crewe began the second half a lot stronger than the first and came out with fresh momentum as Dalla Valle headed just over the cross bar after a good cross by Ajose.
The away side had another chance to equalise less than a minute but Jones’s shot was deflected just over the bar as Walker blew a sigh of relief.
Crewe got an equaliser on 68 minutes after initial great play by Ajose as he turned Wynter inside out to get a cross into the box which Dalla Valle cut back superbly into the path of oncoming Jones who side footed it through Walker’s legs and into the back of the net.
The away side were firmly on the front foot and went 2-1 up with 15 minutes to go after a pass by Anthony Grant eluded the Colchester’s back line as Ajose ran clear and slotted well into the bottom left hand corner past a helpless Walker.
Colchester pushed hard for an equaliser but Grant looked to have ended the game as a contest after he turned in the area and hit a low shot into the bottom corner after hesitant defending.
Colchester sub Jack Marriott gave his side a life line after Fox’s corner caused confusion in the box and Marriott was there to poke the ball home on the line with 5 minutes left to play.
And the U’s were awarded a promising free kick on the edge of the box in the dying seconds but Fox put it just over the bar and it wasn’t enough as Crewe ran out 3-2 winners.
The loss will be a blow to Colchester’s bid to stay up but, with many games remaining, the race for survival is still very much wide open.