Strikers Jabo Ibehre and Gary Alexander caused havoc in the home defence as Orient notched up their first win in five away games.
The game could have taken a very different turn had Carlisle capitalised on their early goal. Brendan McGill volleyed in Karl Hawley third minute cross from five yards after Chris Lumsdon hit an inch perfect pass to Hawley.
It was the home fans expecting an easy afternoon before the Orient onslaught began.
First a clear penalty for a handball was turned down by referee Neil Swardrick before Gary Alexander notched his fourth goal in five games - nodding in a Matthew Lockwood cross.
When Carlisle captain Kevin Gray launched a two-footed challenge on Joe Keith it was Lockwood who smashed home the resulting penalty.
With the pressure building on the Cumbrians' defence a third goal was on the cards for Orient.
But Carlisle almost snatched an undeserved equaliser when Raphael Nade crossed to Hawley to finish but the African striker was pulled back having fouled Lockwood.
When it did come Orient's third goal was a treat coming from Shane Tudor's driving run
The former Cambridge winger out-paced Carlisle midfield Duo Adam Murray and Chris Billy and sliced open the United defence with a through ball to Jabo Ibehre. The powerful centre forward ran onto the ball and flashed an unstoppable drive passed the hapless Anthony Williams.
Orient shut up shop in the second half and, despite Carlisle sending on a third striker, they had limited chances.
Substitute Peter Murphy almost saved the day for Paul Simpson's men after hitting the post with five minutes left before he grabbed a last minute consolation with a fierce drive.
A draw would have been unfair on an impressive Orient side and their fans will have been happy to make the 314 mile back to Brisbane Road with all three points.