Terence Gouyette was accused of committing the grave and criminal assault in Victoria Road in the late hours of 26 June 2019.
But Mr Gouyette denied this, telling the Court that the woman, whom he had never met, was drunk and had been arguing with someone on the phone when he asked her to move, so he could walk through the gate to his front door.
He said she swore at him, prompting him to remark that her language was not very ladylike. This was said to have antagonised the woman, who threw five or six punches at his head. Mr Gouyette said he defended himself by raising his hands and moving forward and to the side.
The Court heard that her own momentum, combined with being drunk, caused the woman to fall on the railings and cut her head, which later required six stitches.
The trial began on Monday and had concluded by Tuesday lunchtime.
The jury of ten women and two men took just under two hours to unanimously find Mr Gouyette, who has worked at the Hospital for 42 years, not guilty of the offence.