The 1,300 tonne roof was lowered high above the ground in a moment which had been planned for four years by Capital and Counties Properties.
Operations Director from Capco’s demolition contractor Keltbray Jim O’Sullivan said: “The lowering of the roof was an extremely delicate operation which was many years in the planning.
"This is the first time that a steel structure of this size has been mechanically lowered some 25m to be disassembled at ground level in the UK.
"I want to give my thanks to the team whose efforts and dedication made this both possible and so well executed and something to be very proud of.”
Capco Managing Director Gary Yardley added: “There is real momentum behind the regeneration of Earls Court and the creation of a vibrant new part of London.
"The lowering of the roof marks a significant milestone and we look forward to continuing this fantastic progress to bring forward London’s newest great estate.”
As part of the ongoing deconstruction of the Earl's Court exhibition halls, the buildings are being dismantled to make way for the hotspot's regeneration of 7,500 new properties.
More shops are also to join the housing to make the area London's newest park when complete.
The development has seen opposition from Liberal Democrat's Caroline Pidgeon and the Earls Court Area Action Group (ECAAG) who have called for an urgent review of the Earls Court Masterplan.
Opponents also argued the loss of the exhibition centres, which are visited by over a million people every year, could cost the area £1.25 billion in lost revenue.