Carlisle’s Sky Bet League tow survival hopes suffered another blow as they went down to a 3-2 defeat at Orient – a fifth defeat in a row.
The visitors have now won just once in 13 games and sit 10 points adrift of safety with 16 games remaining.
However, the Cumbrians stunned their hosts when, against the run of play, they went ahead after 21 minutes when an intended clearance by Omar Beckles struck Josh Vela and cannoned into the net.
But Shaqai Forde turned things around for the Os with two late first-half goals.
Forde received a sublime pass from George Moncur after 40 minutes and drilled his shot wide of goalkeeper Harry Lewis from the edge of the box.
He followed four minutes into first-half stoppage-time when Jordan Brown flicked on a Theo Archibald corner and Forde nodded into the net from close range for his eighth goal of the campaign.
The outcome was sealed in the 57th minutes when Archibald made a quick break out of defence and slipped in Ruel Sotiriou to score.
Sean Maguire scored a late consolation for Carlisle with a penalty deep into added time as their chances of keeping their League One status took another hit.