United controlled the first half and a beautiful goal from Chris Lumsdon put the visitors ahead after just ten minutes.
Canvey's style of play was too laid back and their frontline again failed to function.
In the 34th minute David McGhee netted, but at the wrong end following a corner and his own goal put Carlisle two up.
Then, only six minutes later, Ollie Berquez was shown his second red card in three games for a poor challenge.
To add to Canvey's troubles Danny Potter was also dismissed just before the half-time whistle when Carlisle were awarded a penalty. Lumsdon netted from the spot to double his tally and put the match beyond the home side's reach.
The second half degenerated into a scrappy midfield battle as Carlisle seemed content to defend their three-goal advantage and hang on to the points, although the visitors almost added a fourth when Adam Murray's shot bounced off the crossbar.
In the closing stages the game took another turn for the worse for Canvey when star striker Lee Boylan was taken off injured.
Boylan's injury summed up the Gulls' recent luck and they are now looking over their shoulder at the relegation scrap.