Vivian Walters, prosecuting, told the court: "Coker has 30 previous convictions for burglary - it would appear the majority for offences of a similar nature with elderly victims using a ruse.
"Mrs Jones went to the door and called out 'Who's there?' She was expecting the district nurse to visit her that day in order to change a dressing on her leg.
"She heard no reply so she opened the door a crack.
"He pushed the door open, barged past Mrs Jones and made his way into the flat. In the living room he found her bag, rifled through it and removed her purse."
The court heard how Coker had targeted Mrs Jones the week before the raid on January 24 and that neighbours recognised him and confronted him before being threatened with a knife.
Mrs Jones, a former seamstress who lost her 19-year-old fiance in the First World War, said she has been "frightened ever since" and feels unable to leave the home where she lives alone.
Mrs Jones, who has outlived her seven siblings, told a newspaper: "I think I'm very lucky to have such good neighbours. They are very good to me."
Speaking earlier this year about another attempted burglary, she said: "I don't know if I can recover. It takes its toll. I'm frightened."
Coker, of Charlton, south east London, had pleaded not guilty to the burglary, but changed his plea just before the start of his trial on Tuesday and was jailed for four-and-a-half years.
Judge Stephen Dawson told the jury, who were just about to be sworn in: "It is a sad fact that you would have been a jury where the oldest person in Britain had been burgled.
"But there is a positive side to this as well - there were two good citizens, Michael Madigan and Tracey Simmons, looking after her and doing great things for her and they had the presence of mind to follow the man and bravely keep with him and identify him.
"You had a small touch of history in a way."
Simon Hughes, Liberal Democrat MP for Bermondsey, said: "It is excellent news that the individual who committed these despicable offences has been brought to justice and will be sent to prison for a good length of time.
"All credit must go to Grace Jones who was ready and willing to give evidence to convict her intruder and to her neighbour who chased him and tracked him down.
"Grace Jones is a living legend. Her great sprit shows the best of British in diamond jubilee year - from one of the few people who was also alive when we last had a Queen who celebrated 60 years on the throne."