Orient were on the back foot early on and fell behind to Neil Danns’ effort before Mark Cullen doubled the advantage.
A much-improved second half showing saw Jens Janse score his first goal for the club to give us hope, but we were not able to end our 112-year affiliation with the Football League with a positive result as Andy Taylor struck a third to put the game beyond our reach.
Omer Riza made two changes to the side which lost 3-1 last weekend against Colchester United with Paul McCallum and Tom Parkes making way for Freddy Moncur and Henry Ochieng.
The hosts, keen to secure their spot in the play-offs, were lively from the off and Kyle Vassell had two opportunities in the opening five minutes as he firstly saw a flicked shot fall wide of the target before failing to make the most of a one-on-one situation with O’s goalkeeper Sam Sargeant coming out to save.
Blackpool were dominant and a lovely ball in from Kelvin Mellor found the head of Brad Potts in the box and his glancing header was just wide of Sargeant’s goal.
That dominance was turned into the opening goal on 11 minutes though when former Orient loanee Jack Payne played a ball in for Danns who was able to head home.
Orient had little play in the opposing half throughout the opening exchanges, but forced a first corner after Semedo’s cross was put behind by Tom Aldred, though nothing came from the resultant set piece.
And it was the hosts who doubled their lead on 36 minutes when Cullen took aim from just outside the box and managed to squeeze the ball past the despairing dive of Sargeant.
O’s first real shot in anger almost pulled a goal back as a Callum Kennedy free-kick, at a similar distance to where he scored from at Doncaster, and he forced Sam Slocombe into a top save to tip it round the post.
No changes were made at the break by either side and it was the hosts who once again started brightly with Cullen’s shot well saved by Sargeant before Clark’s clearance.
Ochieng tried his luck from distance with the Tangerines defence easing off, though his strike was comfortable for Slocombe to hold.
The O’s were to find a way back into the game though and Ochieng was the provider as his ball through found Janse who stayed clear of his man and slotted the ball underneath Slocombe to give Orient hope.
Victor Adeboyejo was brought on to give the O’s added firepower up top, but the hosts wasted a golden chance to restore their two-goal cushion when Potts blazed over from close range.
Sargeant was equal to an effort from Vassell but the hosts did score a third when captain Andy Taylor drilled in an effort across goal.
Orient’s young side kept going to the bitter end and Kennedy’s free-kick struck the wall as we went in search of a late second, but it came to no avail.
Sargeant continued to be in top form and did well to deny Vassell before the same player fired wide in stoppage time as the O’s bowed out of the league with a 30th defeat of the season.
BLACKPOOL: Slocombe, Mellor, Taylor, Robertson, Aimson, Payne, Aldred, Danns (Black 70), Potts (Flores 75), Cullen (Gnanduillet 81), Vassell.
SUBS: Lyness, Philliskirk, Osayi-Samuel, Delfouneso.
GOALS: Danns (11), Cullen (36), Taylor (65).
LEYTON ORIENT: Sargeant, Kennedy, Pollock (Happe 84), Clark, Collins, Ochieng, Moncur (Adeboyejo 55), Semedo, Janse, Alzate, Abrahams (Koroma 64).
SUBS: Janata, Dalby, Alderson, Perkins.
GOALS: Janse (50)
REFEREE: David Webb
ATTENDANCE: (951 Leyton Orient fans)