The victim had been walking along Foundry Lane between 10.30pm and 10.45pm when she was attacked.
Also in crime: Police warning after woman in her 80s targeted by phone scammersA West Yorkshire Police spokesman said they were now trying to trace a suspect.
The man was described being of medium build and had dark eyes.
He was wearing dark jeans and a hooded top with the dark coloured hood pulled up.
Any witnesses to the assault are asked to call police on 101, quoting crime reference 13180334765.