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Leyton Orient kept their promotion dream alive with a 2-1 victory over Peterborough United in the second leg of their Sky Bet League 1 Play-Off Semi-Final.
Dean Cox crashed in his 16th goal of the season and Chris Dagnall added a late second to fire Russell Slade's side to Wembley for the first time in 15 years.
Conor Washington pulled one back for Posh in stoppage time but it is Orient, who led the table for much of the campaign only to fall away during the run-in and finish third, who are now just 90 minutes from following Wolves and Brentford into the Championship next season.
The sides were locked at 1-1 after a first leg which Orient had dominated, and they continued in the same vein at Brisbane Road.
They created chance after chance while Peterborough were happy to play on the break, knowing their 33-goal top scorer Britt Assombalonga was lying in wait at the other end.
David Mooney almost fired them ahead in the opening minute from a long throw into the area but was denied by a scrum of defenders and, eventually, goalkeeper Bobby Olejnik.
Kevin Lisbie hit the side-netting with an overhead kick and sent a header narrowly over while Mooney's dipping 20-yard shot flew narrowly wide.
Os midfielder Luke James was next to try his luck with a 25-yarder which had Olejnik scrambling low down to his right to tip the ball around the post.
The chance Posh craved arrived moments into the second half when Danny Swanson was put through by Nicky Ajose - but he made an almighty mess of it.
With Assombalonga pleading for the ball to be squared across the six-yard box for a tap-in, Swanson opted to shoot from the angle and missed by a mile.
If that was a let-off for Orient they were counting their blessings again moments later when Mark Little fired in a fierce, low drive which shaved the post.
Instead it was the hosts who made the breakthrough on the hour mark when they were awarded a free-kick on the edge of the area.
Cox's fierce shot hit Jack Baldwin square in the chest and, unluckily for the Posh defender, bounced straight back to where it had come from.
Cox immediately pounced on the rebound, lashing it past Olejnik to spark wild scenes of celebration behind the goal.
With two minutes remaining Dagnall turned in a pass from fellow substitute Shaun Batt and although Washington bundled home in stoppage time to set up a nervy finale, Orient held out to book a Wembley final against Preston or Rotherham.
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