Jamille Matt netted the opener on the half hour mark, before Tom Aldred doubled the advantage. Substitute Paul McCallum pulled one back for the hosts late on, but it was to prove in vain.
Orient kept faith with the same starting XI, bench and formation which proved successful in last weekend’s 3-0 win at Colchester United.
It was the visitors who started on the front foot, though chances proved to be limited to a long range effort from Brad Potts which went deep into the Tommy Johnston Stand.
Nigel Atangana forced the first opening for the O’s but his weak shot was straight at Sam Slocombe, before Blackpool went up the other end and Cisak was forced into action to deflect a Potts effort behind for a corner.
Gavin Massey launched an O’s attack in his own half, before playing in Simpson who returned the pass to Massey who got a shot away, only for the linesman’s flag to be raised for offside.
The Seasiders were limited to shots from distance as the half drew on, with Colin Daniel firing two efforts way over the bar, before Gary Bowyer’s side did eventually take the lead on the half hour mark.
Striker Jamille Matt was able to shrug off the attentions of Yvan Erichot before coming in off the left wing and firing past Cisak.
The O’s were undeterred by the goal and went their closest yet as Massey received the ball 25 yards out before taking aim and firing against the post.
Cisak was called into action once more as he denied Andy Taylor’s low curling free-kick, before the O’s had the ball in the back of the net once again as the ball kindly fell into the path of Michael Collins who supplied the finish, only for the lineman’s flag to go up once again.
Tom Parkes is not known for his goalscoring prowess but saw one effort blocked and the rebound fell back to the defender but he volleyed over the bar.
He was back in action up the other end minutes later though when doing well to prevent Daniel getting a shot away, with Cisak also in close proximity as the O’s went into the break 1-0 down.
No changes were made at the break by either side but Erichot lasted just seven minutes and was replaced by Alan Dunne.
Kyle Vassell continued to cause the O’s problems and after receiving the ball wide on the left, the striker was able to drift inside and force Cisak to push the effort behind for a corner.
And from that set piece the visitors doubled their lead when Aldred headed home the corner, with protests from the O’s suggesting the goalscorer had used his hand to divert the ball into the net.
Aldred had the ball in the net once more on 65 minutes but the effort was again ruled out for offside, before Kelvin Mellor drilled a shot over the bar when the ball was laid into his path.
Vassell tried his luck from all of 30 yards as the game entered the final 20 minutes, and while Cisak was at full stretch, the effort was wide of the target.
The visitors remained on top, and Cavasin made his final change bringing on Paul McCallum for Ollie Palmer.
Opening goalscorer Matt headed a ball into the path of Potts who chipped an effort over Cisak, but Parkes was there to deny Bowyer’s side a third.
Another substitute Sandro Semedo fired an effort well over as the O’s mounted a swift counter attack from a Blackpool set piece. Time was running out for the O’s though and Semedo unleashed another strike only to see it creep wide of the target.
Orient were not done yet though and pulled a goal back with a minute left on the clock. Dunne’s right wing cross was met by the head of McCallum who directed into the top corner to give the hosts a lifeline.
A minimum of five minutes of stoppage time was awarded and skipper Robbie Weir was denied a first goal when his shot was blocked behind for a corner, but that proved to be the final chance as Orient lost out.
Orient: Cisak, Hunt, Erichot (Dunne 52), Parkes, Kennedy, Weir, Collins (Semedo 66), Massey, Atangana, Palmer (McCallum 75) , Simpson.
Subs: Sargeant, Pollock, Adeboyejo, Ochieng.
Goals: McCallum (89)
Booked: Weir (64)
Blackpool: Slocombe, Mellor, Aldred, Robertson, Taylor, Payne, Pugh, Potts, Daniel (McAllister 82), Matt (Gnanduillet 85), Vassell (Philliskirk 90+4).
Subs: Boney, Cullen, Nolan, Osayi-Samuel.
Goals: Matt (30), Aldred (58)
Booked: Aldred (51), Daniel (60), Taylor (80)
Attendance: 4,376 (361 Blackpool fans)
Referee: Brendan Malone.