Aiden Hubbard-Stewart was made the subject of the order due to his previous behaviour towards the woman, who was known to him.
Despite this, he followed and then slapped the woman in Canterbury in June this year, then attacked her again in July, causing serious injuries.
The 21-year-old was arrested three days after the second attack and was later charged with multiple offences.
At Canterbury Crown Court on 13 August, he admitted unlawful wounding, assault, witness intimidation and breach of a non-molestation order.
Hubbard-Stewart, of Hunton Gardens, Canterbury, was brought back before the same court on 10 September and jailed for four years.
The first incident took place at Canterbury East railway station on Friday 11 June, when, despite being subject of the non-contact order, Hubbard-Stewart approached the victim and another woman.
He then slapped the victim in the face and stole her mobile phone, which he later returned via a relative.
In the days after the incident, Hubbard-Stewart repeatedly contacted the woman who had witnessed the assault, putting pressure on her to withdraw her evidence.
On 7 July, after the court order had expired, Hubbard-Stewart followed the victim in the Forty Acres Road area of Canterbury before making threats and then punching her to the ground. She suffered serious injuries which required long-term medical treatment.
Hubbard-Stewart then tried to evade arrest and repeatedly attempted to call the victim before he was arrested while trying to climb out of the window of a property in Cliftonville on 10 July.
As part of his sentencing, an indefinite restraining order was imposed to protect the victim and her family.
Detective Constable Sam Mayne, of Kent Police’s Vulnerability Investigation Team, said: ‘Hubbard-Stewart put this victim through a harrowing ordeal and I would like to praise her courage in supporting our investigation and this prosecution.
‘I hope the speed at which the case has been brought to a conclusion offers her some comfort as she recovers from these distressing offences.
‘I encourage anyone who is being harassed, abused or controlled by a partner, ex-partner or anyone known to them to contact Kent Police as soon as possible. We will find a solution which best suits you and work to bring offenders before