West Ham endured having to play most of the second half with the on-loan Arsenal midfielder Henri Lansbury in goal to hold on for a victory last night that moves them to the top of the Championship.
With a lead secured by goals from James Tomkins and Nicky Maynard, who scored his first since joining from Bristol City in a £1.65m deal on deadline day, Sam Allardyce's side saw their advantage halved by Kevin Phillips.
Their numbers were also reduced when Green was sent off for a trip on Roman Bednar, with Lansbury, who was serenaded as "England's No 1" and "Are you Ludo in disguise?" – as a nod to former West Ham goalkeeper Ludek Miklosko – having to come on to replace him in goal.
But despite having to play with 10 men for the third straight game, the visitors secured the points when Gary O'Neil and Ricardo Vaz Te added two goals on the break in a performance that had all the hallmarks of promotion certainties.
"The way they've been playing, to win here with 10 men shows you the size of the victory. To do it with 10 men, with an outfield player in goal, was just outstanding," Allardyce said.
"It was a poor decision that we've overcome again and that's seven points out of nine with 10 men but we've got to stop it because my heart can't stand it.
"He doesn't practice in training but Henri tells us he's played before and has no fears about doing it at all but he did the job," the West Ham manager added.
The visitors were well worth their two-goal lead secured when Tomkins headed in from Mark Noble's free-kick and Maynard touched in from Jack Collison's cross before Kevin Phillips pulled one back with a header from Alex Baptiste's cross in first-half added time.
But despite Green's dismissal seven minutes after half-time, Lansbury was untested and O'Neil thumped in a third through a crowd of bodies before Vaz Te broke away to have a shot deflected in off Craig Cathcart to leave Blackpool, who could have moved up to third if results had gone their way, out of the top six.
"I took a massive gamble at half time and it back-fired," manager Ian Holloway said. "I made all three subs and he cleans him out so we've both effectively got 10 men because Bednar could barely move for the rest of the game.
"They looked like potential champions and we looked like people who should sort their lives out."
Blackpool (4-4-2): Gilks; Baptiste, Evatt, Cathcart, Crainey; Basham (K Phillips, 35), Ferguson, Sylvestre, Fleck; M Phillips, LuaLua. Substitutes not used Eardley, Dicko, Bednar, Wilson.
West Ham United (4-1-4-1): Green; O'Brien, Reid, Faye (O'Neil, 66), McCartney; Tomkins; Faubert (Lansbury, 54), Noble, Collison, Vaz Te; Maynard (Cole, 82). Substitutes not used Baldock, Potts.
Referee O Langford (West Midlands).