Ten fire engines and around 70 firefighters were called to a fire at a shop with flats above on High Road in Chadwell Heath.
A first floor flat was destroyed by the fire and part of the roof of the building was damaged. A small part of the ground floor shop was also damaged. There were no reports of any injuries.
Station Commander Nathan Hobson, who was at the scene, said: "There was a lot of thick smoke issuing from the building when firefighters arrived.
"Crews worked hard to contain the blaze and bring it under control."
The Brigade was called at 0330 and the fire was under control by 0509. Fire crews from Barking, Ilford, Romford, Hornchurch, Dagenham and surrounding fire stations were at the scene.
The cause of the fire has been recorded as undetermined.