The pair, who targeted a Harvey and Thompson pawnbrokers on Atlantic Road, have now been jailed for a total of 20 years.
On May 27, Michael Lindo, 34, and Aaron Anthony Dumetz, 24, arrived at the shop at 9 am – both dressed in burkas.
The robbers threatened two female staff members with an imitation firearm and forced them to open the pawnbroker’s safe.
The duo then got their hands on over £44,000 worth of jewellery and more than £10,000 in cash.
However, members of the public had noticed the pair and became suspicious because “hey did not walk like women, Inner London Crown Court heard.
They raised the alarm and unarmed officers confronted Lindo and Dumetz, chasing and catching them after the pair fled.
Judge Nic Madge said the raid would have involved “reconnaissance and careful planning” to acquire the burkas and a fake firearm.
The court heard that Lindo, a football coach, had an “appalling previous record”, with 19 previous convictions for robbery or attempted robbery, two involving firearms.
He was sentenced to 11 years’ imprisonment and Dumetz, a trainee carpenter, received a custodial sentence of nine years.
The judge added that it would have been difficult to identify the robbers because of their disguise if members of the public had not intervened.
Investigating officer DS Gary Ferguson of The Flying Squad, East London Branch, said: “On behalf of the Met’s Flying Squad I would like to thank the local Lambeth Police officers, who bravely followed the two robbers from the scene and tackled them, despite not knowing at that time if the firearm used on the robbery was real or not.
“It was these officers and members of the public, who reported the two robbers actions to police, that has secured the conviction of these two men and the recovery of a substantial amount of stolen jewellery and cash. Lindo in particular is a career criminal and this timely intervention has averted a serious threat to public safety and commercial premises in particular.”