Revellers are being warned to keep their behaviour in check when they hit the town for the final weekend before Christmas.
Police in major cities had a busy night on what has become known as "Mad Friday", when pubs and bars become rammed with people looking to end the week before Christmas on a high.
Thousands of people, many dressed in festive attire, were photographed enjoying themselves in cities including Newcastle, Cardiff, Swansea, Manchester and Sheffield.
Mad Friday is considered to be one of the booziest nights of the year, with plenty of people throwing caution to the wind knowing they have days to recover.
But officials have urged people to avoid trouble and the risk of spending the most wonderful time of the year behind bars.
Jon Simpson, the city centre sergeant for Sheffield, said: "Make sure you've got a plan for getting home and don't put yourself in a position where you make yourself vulnerable and potentially end up a victim of crime.
"You also don't want to commit crime and end up in a police cell over the Christmas period."
Police deployed extra officers in some alcohol hot-spots on Friday night to deal with any disturbances.
One man was seen being restrained and piled into the back of a police van in Swansea, while two others were captured squaring up to one another in Newcastle.
In Middleton in Greater Manchester, a male police officer was knocked unconscious and a female colleague dragged to the floor and stamped on as they intervened in a fight near a pub.
The pair were responding to another call when they saw a large group of men fighting in Long Street at 2.35am.
Both officers were taken to hospital but have been discharged and no arrests have been made, with the suspected attackers fleeing the scene.
Detective Sergeant Tim O'Callaghan, of Greater Manchester Police's (GMP) Rochdale division, said: "We will not tolerate this kind of behaviour and are 100% committed to bringing those responsible to justice."
GMP described one of the attackers as white, of medium build with short brown hair and a beard, and was wearing a dark T-shirt, trousers and trainers.
Another was white, of medium build, around 6ft tall and in his early 30s. He had short dark hair and stubble, and was wearing a black-belted coat, blue or grey jeans with ripped knees and dark shoes.
Police have asked people to try to avoid any situations that could cause them potential harm so not to put any unnecessary strain on the emergency services.
Aberdeen Chief Inspector Rob Sturton said: "Think before you act; a split-second decision can change your life."
Other advice issued by police for any boozy nights out over Christmas include: