Darren Ferguson has admitted that clinical finishing was the difference as Peterborough United suffered League One playoff heartbreak at the hands of Leyton Orient.

Posh lost 2-1 at Brisbane Road on Tuesday to suffer a 3-2 aggregate defeat in their semi-final against the O's, but missed several good chances, including when Danny Swanson chose to shoot from a tight angle rather than cross for 33-goal striker Britt Assombalonga to tap in.

United boss Ferguson has conceded that his side's decision making in the final third was not good enough, but nevertheless hinted that Orient were perhaps fortunate to win across the two legs.

"The difference on the night was they were more clinical," he told reporters. "To have four three-on-three situations in the first 45 minutes and not take advantage of any of them, that was our downfall.

"In my opinion I don't know if Orient have done enough over the two legs to go through, but they have done. So I have to congratulate Orient and I really hope they go on and win it now."

Orient will face either Rotherham United or Preston North End in the final later this month.