Abrar Khan, 30, befriended the vulnerable woman, in her 60s, near Lendal Bridge, York, on January 2 earlier this year.
He then led her down the side of the River Ouse to a cold, wet and muddy spot behind St Peter’s School at around 7pm.
There, he threatened to kill her, pushed her to the ground and raped her before kicking her in the face and beating her several times.
Khan then stole all the money she had on her person, a total of £2.60, before leaving her in the dark with a battered and bleeding face, neck and chin.
He had been released from prison just 11 days before and was staying at the probation hostel in Boroughbridge Road on parole.
After the victim reported the attack, police then sifted through hundreds of hours of CCTV before they spotted Khan.
He was arrested two days later and also identified with DNA evidence.
DI Steve Menzies of the North Yorkshire Major Investigation Team said: ‘I can only describe Abrar Khan’s actions as a despicable, violent and cowardly sexual attack on a vulnerable lady.
‘At the time of the offence, Khan was on licence from prison following another attack on a vulnerable woman in South Yorkshire in July 2012.
‘It is clear that he believed targeting vulnerable members of our communities would help him in evading capture.
‘This outcome at court clearly shows he was wrong.’
In 2012, Khan had been jailed for attacking a Sheffield woman in what the prosecution had initially called an attempted rape.
The prosecution dropped the charge when Khan admitted assault with intent to rob and he was jailed for five years.
At the time, Judge Michael Murphy QC had warned him: ‘If in the future there is another matter like this, or remotely like this, life imprisonment will be the inevitable sentence.’
On Friday, October 12, Khan, of no fixed address, was jailed for life with a minimum term of eight years.
He has also been put on the sex offenders’ register and made subject to a restraining order banning him from contacting the victim.
Judge Andrew Stubbs QC said: ‘I am entirely satisfied the seriousness of the rape and associated robbery justifies in your situation imprisonment for life.’
Defending, Laura Marshall stated that Khan had ‘buried his head in the sand’ after his brother had been jailed for murder.
‘This young man for the past almost 18 years has been trying unsuccessfully to cope with what had happened to him,’ she told the court.
‘He is appalled and he is ashamed of his behaviour.’