Orient came from a goal down to pick up a vital victory over 10-man Port Vale after a second half turnaround.
O’s trailed at the break after Chris Birchall netted from an acute angle after 28 minutes, before David Mooney slotted home a 55th minute penalty after Chris Dagnall was fouled by goalkeeper Chris Neal, who was subsequently sent off.
Neill Collins’ own goal put the hosts into a vital lead, and despite a penalty miss from Mooney, Dean Cox rounded it off with a late third.
Orient boss Fabio Liverani made four changes from the side which lost 1-0 at Crawley Town, with Gary Sawyer, Mathieu Baudry, David Mooney and new loan signing Jake Taylor in for the Andrea Dossena, Nathan Clarke, Darius Henderson and Ryan Hedges respectively.
It was a slow start to the game, though the Valiants dominated the possession as they forced two early corners, though both failed to trouble the O’s.
But the first real chance of match fell to the hosts after 10 minutes when Marvin Bartley’s teasing ball into the box was just gathered by away goalkeeper Chris Neal with Chris Dagnall ready to pounce.
Opportunities were few and far between until Alex Cisak was forced into a fine save to deny Louis Dodds after a poor clearance fell to him just inside the box.
The visitors kept up the pressure and from the resulting corner Chris Robertson’s effort was cleared off the line by Gary Sawyer as Rob Page’s side began to build up some momentum.
And they took the lead with 28 minutes on the clock as a long ball over the top found Chris Birchall down the right who raced on to the ball and fired low past Cisak from a tight angle.
They almost built on that a minute late when Frederic Veseli managed to get a dangerous ball into the box, but despite a despairing dive Mark Marshall was unable to get a decisive touch on the ball.
Pope directed a header straight at Cisak from a left-wing cross and Pope went even closer seconds later when he beat the offside trap before seeing an effort partially saved by Cisak, before Baudry cleared the ball off the line.
Orient were struggling to get a foothold in the game, but Josh Wright’s ball forward found Mooney who took one touch before a curling effort was well tipped over by Neal.
And from the resulting corner the danger wasn’t fully cleared by the Port Vale defence and a ball into the box found its way to Dagnall at the back post but his effort was off target.
Orient ended the half on top and a corner was cleared straight to Taylor, though he saw his strike flash well wide of Neal’s goal.
It was now Dagnall’s opportunity to get the ball into the box and an acrobatic effort from Cox just inside the box struck the upright as Orient ended the half with some good play despite trailing.
There were no changes at the break from either side, but the O’s started as they ended the first half when Dagnall was superbly denied by Neal after Cox’s ball through for Orient’s top goalscorer.
But the turning point of the game came when 10 minutes into the second half when Dagnall was through on goal and Neal brought down the striker.
The Vale goalkeeper was then shown his marching orders and Mooney stepped up to take a penalty after a long delay as goalkeeper Sam Johnson came on for Junior.
Despite the delay Mooney remained calm and sent Johnston the wrong way from the spot as the O’s levelled, and held the numerical advantage.
Orient built on that and Mooney went agonisingly close minutes later when his shot was kept out Johnston, and the rebound found Dagnall but he struck the post.
And they eventually turned the pressure into a second goal when a ball in from Sawyer found Taylor at the back post who directed a header back across goal and loanee Neill Collins directed the ball into his own net after 61 minutes.
They continued to build on that and a ball in from Taylor was mishit by Cox but Johnson reacted well and gathered.
Josh Wright then played in Cox who turned on the ball only to see the sub goalkeeper save low down to his right
And the O’s had the perfect opportunity to seal all three points when Mooney was brought down by Johnson, and referee Darren Handley pointed to the spot for the second time.
However, this time the goalkeeper atoned for the error by making a comfortable save.
The visitors kept plugging away though and the O’s had to be thankful for sub Nathan Clarke after his fine clearance denied Vale an equaliser following Ben Williamson’s blocked shot.
Williamson then took aim after winning a free-kick and Cisak had to be at his best to punch clear. But as gaps opened up at the back with the visitors pushing for a leveller Orient took full advantage as a quick breakaway saw substitute Gianvito Plasmati find Cox.
And he ran down on goal before firing his shot past Johnston to make sure of all three points.
Lloyd James received a rapturous round of applause when replacing Taylor late on, and Dagnall again went close as he struck the bar late on as Orient went on to record a vital win.
ORIENT: Cisak, Sawyer, Baudry, Cuthbert, O’Neill (Clarke 67’), Cox, Wright, Bartley, Taylor (James 86’), Mooney (Plasmati 78’), Dagnall.
SUBS: Omozusi, Henderson, Simpson, Woods.
GOALS: Mooney 55’ (pen), Collins OG 61’ Cox 84’
PORT VALE: Neal, Dickinson, Robertson, Birchall (Daniel 69’), Dodds, Pope (Williamson 69’), O’Connor, Collins, Marshall, Veseli, Junior (Johnson 55’)
SUBS: Yates, McGivern, Coulibaly, Campion.
BOOKINGS: Junior 38’ Robertson 78’
RED CARDS: Neal 55’