The attack took place between 3.45pm and 4pm on Sunday in Anglesea Road, close to the University of Portsmouth buildings.
The woman, who is in her 40s, was taken to hospital with injuries to her arm. She has since been discharged, police said.
A spokeswoman from Hampshire police added: ‘Officers attended and arrested a 42-year-old man from East Sussex on suspicion of wounding/inflicting grievous bodily harm.
‘He has been released from custody on conditional police bail while our enquiries continue.
‘As part of our investigation into this incident, we would like to hear from anyone who saw what happened.
‘Perhaps you were travelling through the area at the time and have dash cam footage that may assist our enquiries?’
Those with any information can call police on 101, quoting reference number 44220265116.
Alternatively, go online and submit information via the following form: hampshire.police.uk/tua/tell-us-about/cor/tell-us-about-existing-case-report/