Pc Natasha Haf Jones, 38, of North Wales Police, had attended the function at Garthmyl Hall country house near Welshpool in Mid Wales, with her husband, last October. She landed up in court.
Now her chief constable Carl Foulkes has fired her for gross misconduct after a disciplinary hearing.
Prosecutor Rhian Jackson had told Llandudno court previously how the off-duty officer, from Dolgellau, had travelled to the luxury venue with other guests on a bus.
“The guests who arrived on the bus from Dolgellau are described as being drunk on arrival. The manager states that many of them were falling over drunk and the group were one of the rowdiest the venue had in a long time,” Mrs Jackson said.
Caretaker Andrew Reeve had been working in the bar during the evening and told by a glass collector that two people were fighting including the policewoman.
Jones had pushed past her brother and Mr Reeve feared she was going to “kick off” with someone and put his arms up in a gesture to stop her passing him.
Mrs Jackson said she reacted by punching him in the face.
She was saying: "I’m a police sergeant.”
The defendant’s brother and another woman grabbed Jones and they ended up rolling around on the floor.
Later Jones was seen slouched in a corner with her head in her hands and upset. The prosecutor said the policewoman “became aggressive and was swinging punches at her brother and trying to strangle him.”
The pair were split up and Jones’s husband was told she needed to leave the venue. However, Jones had called Mr Reeve a “fat b*****d” in a corridor.
The prosecutor said Jones walked towards him and he shouted for police to be called.
“Mr Reeve states that Natasha Haf Jones got right into his face and said 'I’m the f*****g police. Let’s see what happens when they get here and who they listen to’.”
She lunged towards him in an unsuccessful bid to headbutt him, he believed.
Jones had also smashed her sister-in-law’s head against a wall.
When police attended, Jones told a Pc not to put his hands on her as she was a police sergeant and “let the f*** go".
Mrs Jackson added that Mr Reeve had been shocked by the trouble at the nice venue and he didn’t expect it as “there were a lot of police officers present at the wedding".
Jones admitted three common assaults on Mr Reeve and Caroline Roberts.
Richard Black, defending, said Jones had anxiety and depression. Previously she’d arrested a man, who she knew, for domestic violence and during the hour-long journey from Dolgellau to custody at Caernarfon she had been subjected to a barrage of personal abuse and threats.
“She says she’s a hardened police officer. But for some reason this incident had a massive effect on her,” Mr Black said.
“She had already been suffering with cutbacks and lack of officers. This seemed to be the straw that broke the camel’s back.”
She had been a regular drinker and a rugby player but had cut back on alcohol.
The lawyer said : "This was the first big night out ‘on the lash’.”
Mr Black said Jones faced the sack after 13 years as a police officer and PCSO.
He added :“My client wishes to express her apologies publicly. She’s made peace with her sister-in law.”
District judge Gwyn Jones had told Jones: "It’s clear to me you consumed a copious and excessive amount of alcohol which had a significant impact.
“During the course of your experience with the police service both in North Wales and Dyfed Powys I would have thought the consequences of drinking too much ought to have been clear to you.”
The judge said: "This is a significant fall from grace. You were extremely well-regarded.”
Jones was told to do 160 hours unpaid work and pay £300 compensation to Mr Reeve and £340 costs.