The game was only a minute old when Matty Robson latched on to a cross from JP McGovern to give Carlisle the lead over a Coventry side looking to extend a record of six away wins in a row.
Ninety five minutes of football later it was still the only thing separating the sides.
t was a huge improvement on the Blues last outing when they were beaten 4-0 by Swindon.
Liam Noble and Lee Miller both spurned chances to extend United's lead, while two shocking misses by Coventry's Leon Clarke will have been a bitter pill for away fans to swallow.
Carlisle are now 17th in League One, nineteen points above the relegation zone.
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Wintry start for some and windy. Brightening later
Emma brings you Saturday's forecast
Longest cold spell of winter so far. Mainly dry and bright, but feeling bitterly cold today. Very wintry further east, blizzards possible