KNUTSFORD were denied a victory when Carrington scored a decisive try in the last minute.
A successful conversion followed, inflicting on Blues a third defeat in their past four matches in the North West Intermediate League's Division Three South.
It had appeared that the home team would eke out a victory despite not being at their best.
All was going according to plan when Ted Cawson capped a strong start by claiming the game's first try.
However Carrington punished a mistake when one of their wings collected a wayward kick and dotted down between the posts.
Knutsford, for whom debutant Rob Richardson delivered a man-of-the-match performance, responded when Adam Ellary went over on the half-hour.
They made changes for the second-half in a bid to find more fluency, but continued to concede territory.
A lack of discipline led to Alex Cartney and stand-in skipper Jim Southall spending time in the sin-bin too.
Southall did score upon his return, while Ellary's penalty kick with five minutes left edged his side in front at 20-17.
However their hopes of recording a fourth league win were dashed when their guests crossed the whitewash with time running out.
They are hoping for a change of fortune on Saturday, when their destination is Didsbury Toc-H to take on the host club's third team.
On arrival they'll be greeted by out-of-sorts opponents that have lost seven successive matches in all competitions.
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