Officers were called to Church Place at 3.50am following reports of a woman being sexually assaulted.
According to police, the woman was approached and dragged into a grassy area when she was walking in South Ealing Road.
Police say she was then attacked but was able to bite the suspect's hand and get away, running to a friend's house nearby to call police.
The woman was later treated for minor injuries.
"The victim was subjected to a terrifying attack by a stranger in the dead of night, and we need to catch the person responsible," said detective sergeant Dan Langton.
Adding: "We have released an image of a man we would like to speak to in connection with this incident.
"If you recognise him or you have any information about the incident, please call us."
The suspect is described as being around 5ft 8ins tall, of middle-eastern in appearance, with short brown hair.
He was wearing a white T-shirt, blue jeans, black shoes and is believed to have had a black puffa-style jacket.
No arrests have been made.
Anyone with information relating to the incident is asked to call police on 101 or anonymously via Crimestoppers on 0800 555 111.
Information can also be Tweeted to police @MetCC, or emailed to SapphireNW.WitnessAppeal@met.pn.police.uk.
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