Victor Obinnaâ€™s double was backed up by a Robbie Keane strike on his Hammers debut as Avram Grantâ€™s men picked themselves and moved into 18th position.
The loss, which was their fourth in a row, forced the Seasiders down to 13th and suggests Ian Holloway has a few problems as his side continues to leak goals.
GOAL West Ham took the lead after 24 minutes when Blackpool keeper Richard Kingson produced an absolute howler. Victor Obinna took a short corner from James Tomkins, turning Seasiders defender Craig Cathcart twice, before shooting on goal but Kingson somehow let it slip through his hands for the opener.
Hammers defender Danny Gabbidon came off with a hamstring injury just after the half-hour mark, replaced by Winston Reid but it seemed the visiting defence were having little to do.
GOAL West Ham debutant Robbie Keane made it 2-0 when he received the ball about ten yards after Kingson made a double save from Obinna and the former Tottenham man made no mistake, slicing home in the 37th minute.
GOAL Despite not having a clear cut chance, Blackpool got one back in the 41st minute when Charlie Adam managed to score a great goal when he swung it in from the corner, the ball beating Hammers keeper Robert Green who appeared to be unsighted.
GOAL But moments later, West Ham made it 3-1 when Scott Parker teed up Obinna, who was clearly up for it today, and the Nigerian powered home from 25 yards to give his side a two-goal lead at the break and grab his second for the match.
The second half was nowhere near as thrilling as the opening 45 minutes as West Ham were keen to sit on their lead whilst Blackpool attempted, in vain, to get themselves back into the contest.
There was no change to the score when referee Stuart Attwell blew the final whistle as West Ham picked up a great win on the road.
Richard Kingson (gk), David Carney, Alex Baptiste, Neil Eardley, Craig Cathcart, Charlie Adam (Evatt 46â€™), Andy Reid (Harewood 60â€™), David Vaughan, DJ Campbell, Luke Varney (Beattie 61â€™), Gary Taylor-Fletcher
Subs - Paul Rachubka (gk), Ian Evatt (46â€™), Marlon Harewood (60â€™), James Beattie (61â€™)
Robert Green (gk), Wayne Bridge, Danny Gabbidon (Reid 33â€™), Lars Jacobsen, James Tomkins, Gary Oâ€™Neil, Scott Parker, Mark Noble, Frederic Piquionne, Robbie Keane (Boa Morte 83â€™), Victor Obinna (Kovac 83â€™)
Subs - Ruud Boffin (gk), Winston Reid (33â€™), Luis Boa Morte (83â€™), Radoslav Kovac (83â€™)