Crewe threw away the chance of cashing in on Cardiff's failings when they too went down to a shock home defeat - 1-0 at the hands of Swindon.
While news of the Bluebirds' 3-0 reverse against Colchester filtered around the Gresty Road, the Cheshire side laboured to make headway.
Then Stefani Miglioranzi's 75th minute drive from the edge of the box flew through Clayton Ince's grasp to hand the three points to Andy King's side.
The Railwaymen were below par for most of the afternoon against modest opposition.
Their clearest openings fell to midfielder Kenny Lunt, but he wasted two gilt-edged chances to put his side in front before the break.
When Steve Foster's challenge on a Town defender saw the ball spin loose into his path, Lunt dragged his effort hopelessly wide from ten yards.
It got worse moments later for the player, who had scored both of Crewe's goals in their last two outings against Blackpool and Bristol City.
Steve Jones burst clear on the left of the box in the 36th minute and was upended by the careless outstretched boot of Alan Reeves.
But Lunt slotted a hesitant penalty weakly against Bart Griemink's right-hand post to huge groans.
Steve Foster then shot straight at the keeper from a juicy position inside the box, before Sam Parkin was equally wasteful when he headed David Duke's cross over from point-blank range.
Dean Ashton came close to a breakthrough with a 30-yard free kick, which he whistled past the post in the second-half, but Crewe were struggling to make an impression.
And a moment of hesitancy at the other end let in Danny Invincibile, only for him to delay shooting and Ince made an easy save.
But the home keeper was beaten when Miglioranzi let fly from the edge of the box and the ball appeared to take a deflection before flying through his clutches into the top corner.