A police detective sergeant accused of attacking a holidaymaker in a pub admitted he had been on the premises for seven hours before the brawl.
Paul Whiteley, 50, said he and girlfriend Claire Hughes, 43, had shared two and a half bottles of red wine during the afternoon at the Fylingdales Inn, Fylingthorpe, near Whitby, North Yorkshire.
But he denied Hughes intended to drive them both back to the camp site where they had been staying.
He told Scarborough Magistrates the couple intended to walk back - but needed their umbrellas and some other things from the car because it was raining.
He claimed while they were heading to the car, alleged victim Carl Sarsfield, 41, started yelling at Mrs Hughes that she was a “disgrace”.
The policeman, a serving officer for more than 22 years, seven of them with the West Yorkshire Police Homicide and Major Enquiry Team, said he told Mr Sarsfield he was a police officer in a bid to calm the situation down.
He denied ripping his shirt off or slapping Mr Sarsfield in the face.
He had taken his shirt off because he had been sweating, intending to walk home in just a coat and jumper.
He claimed Mr Sarsfield had struck the first blow “for no reason,” adding: “I saw it coming and stuck out my arm to deflect the punch.”
The next thing he knew he was on his back and Mr Sarsfield was on top of him, punching him in his head and body, until he managed to roll over and get to his feet.
“I tried to calm him down and said ‘You need to stop what you are doing’ and to my surprise he did,” Det Sgt Whiteley added.
He denied while he was waiting for police he had given the impression he had nothing to worry about because he was serving officer.
“No. I would not do that,” he added.
Hughes denied all claims that she had attacked Mr Sarsfield’s girlfriend Paula Crossley, 41, during the incident in May last year.
Whiteley, of Grange Moor, Wakefield, and Hughes, of Fulford Place, Hospital Fields Road, York, both deny assault by beating.
The trial continues.