Sam Allardyce's side will take on Cardiff for a place at Wembley after the Bluebirds clinched the final play-off spot with a win at Crystal Palace
Two goals from Carlton Cole helped the Hammers to victory against Nick Barmby's side despite Corry Evans' late header but Southampton's win at home to Coventry denied the east Londoners the chance to immediately return to the top flight.
The Saints swept to a second-placed finish with a 4-0 win over the Sky Blues at St. Mary's with Billy Sharp, Jose Fonte and Adam Lallana amongst the scorers.
Sam Allardyce's side will tackle Cardiff in the play-off semi-finals after the Bluebirds grabbed sixth place with a win at Crystal Palace, Peter Whittingham cancelling out Wilfried Zaha's opener before Don Cowie's winner.
Middlesbrough could have stolen the final play-off spot away from Malky Mackay's side, but they lost at Watford with Chris Iwelumo netting for the Hornets before Marvin Emnes equalised late on and Troy Deeney hit an even later winner.
Birmingham and Blackpool will compete in the other play-off semi. The Blues secured a fourth-placed finish and a home second leg with a fine win over champions Reading - Adam Rooney and Wade Elliott on the scoresheet in a 2-0 win.
Meanwhile, the Tangerines were held to a 2-2 draw by Millwall with Andy Keogh and Harry Kane scoring for the Lions whilst Ian Evatt and Nouha Dicko scored for Ian Holloway's side.
The relegation places had already been confirmed before the final day but bottom of the table Doncaster Rovers rounded off a miserable season with a 3-2 defeat to Ipswich Town at the Keepmoat stadium.
Portsmouth will also be plying their trade in League One next term and they finished the highest of the bottom three despite a Dexter Blackstock double firing Nottingham Forest to victory over Pompey at the City Ground.
Brighton held a play-off spot for much of the campaign but poor form at the end of the season has cost Gus Poyet's side, they played out a 0-0 with Barnsley at Oakwell.
Derby County secured a top-half finish under Nigel Clough as Theo Robinson's goal cancelled out David Ball's opener in a 1-1 draw with Darren Ferguson's Peterborough United.
Burnley and Bristol City drew 1-1 at Turf Moor, Danny Ings scoring for the Clarets and Shaun Taylor scoring for Derek McInnes' side.
Elsewhere, Leicester City, pre-season favourites for promotion, ensured they finished ninth as Martyn Waghorn and Harry Panayiotou scored in a 2-1 over Leeds United at Elland Road.