The Hammers were relegated to the Championship after losing 3-2 at Wigan and Grant has instantly paid the price after his side squandered a 2-0 first-half lead en route to the Football League.
And Grant was given the boot - as exclusively revealed by Sportsmail - just eleven months after replacing Gianfranco Zola in the Upton Park hot-seat on a four year deal.
Sacked! Grant has been shown the exit after the Hammers sunk into the Championship
Co-owners David Sullivan and David Gold have decided to take action to give Grant's successor enough time to rebuild for next season with automatic promotion at the top of the new manager's in-tray.
A club statement confirmed: 'The club can confirm that Avram Grant is no longer the manager of West Ham United.
'First-team coach Kevin Keen will take charge of the team for the final home match of the season against Sunderland on Sunday 22 May.'
Over and out: Parker's career with the Hammers is also in its final stages now relegation has been confirmed
Sullivan and Gold swiftly moved to end the 56-year-old's brief tenure ahead of next Sunday's final Premier League clash against Sunderland to avoid any ugly confrontations with angry Hammers fans at Upton Park, aggrieved at the club's exit from the top flight.
Martin O'Neill was courted for the position back in January before he opted against the move to east London. QPR manager Neil Warnock, Watford boss Malky Mackay, Cardiff's Dave Jones and Notts County chief Martin Allen are all believed to be on the shortlistof candidates devised by the club.
People power: The board and fans lost faith with Grant
Crashing down: Jack Collison looks distraught as the news sink in of West Ham's fate
Gold admitted recently that a host ofthe club's key players will be sold this summer after Sullivan estimated the cost of relegation will be a hefty ?40million.
Footballer of the Year Scott Parker is certain to attract interest from a host of Premier League suitors with Tottenham leading the race to sign him.
Hammered: Defeat at Wigan confirmed the East End club's demise
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Explore more:People: Martin O'Neill, Gianfranco Zola, Neil Warnock, David Gold, Martin Allen, David Sullivan Places: Cardiff, London Organisations: Football League