Neil McNulty was out celebrating his birthday on the night of the incident
A 19-year-old man has admitted the manslaughter of a mother-of-three who died when he threw a bottle into a crowded pub after being refused entry.
A shard of glass struck Emma O'Kane in the neck in an "incredible mishap", Manchester Crown Court was told.
The 27-year-old part-time barmaid at the Queen Anne Hotel in Heywood, Greater Manchester, bled to death.
Neil McNulty, of Peel Lane, Heywood, was told he faced an "inevitable" custodial sentence.
The Crown Prosecution Service (CPS) accepted his plea of not guilty to murder on the grounds that there was no realistic prospect of securing a conviction on the charge.
Ms O'Kane was in the pub to celebrate the birthday of her partner, Michael Shepherd, and the couple, who have three children, were planning to marry.
She worked as a barmaid at the pub, but was off duty at the time of the incident on 27 December.
The glass severed her jugular vein and an artery.
McNulty was also enjoying his own birthday drinks on a night out but became abusive when he and his friends were not allowed inside the Market Street pub.
David Steer QC, prosecuting, said a friend of the defendant attempted to gain admission shortly after 0130 GMT but was denied as he appeared injured and bleeding.
Ms O'Kane died after a shard of glass severed a vein and artery
The man became abusive and was then joined by McNulty and another friend who joined in the disturbance.
Staff decided to close the door to prevent further trouble but bar manageress Kimberley Walker later went outside with doorman Rodney Cateley to speak to the men, Mr Steer said.
She saw that McNulty had his hooded top up and removed it before he put it back up again.
Mr Steer said: "He shouted threats. He was in possession of a bottle. He stepped back into the road and from a distance of 10 to 15 feet he threw it with considerable force in the direction of Rodney Cateley.
"He ducked to avoid the bottle. It smashed on a pillar in the premises and unfortunately the deceased was standing inside.
"By an incredible mishap a piece of glass hit her neck."
Ms O'Kane, who was bleeding profusely, was rushed to hospital, but later died.
The prosecutor said McNulty was unaware of what had happened inside the pub and continued to behave violently before he eventually left the scene.
He voluntarily attended a police station the following afternoon and told detectives he thought he had thrown the bottle at a closed door.
McNulty said he had known Ms O'Kane, from Heywood, and her family since he was a child and was said to be "devastated" at her death.
Mr Steer said: "The prosecution do not accept he threw it at the door. He threw it in the direction of the doorman. CCTV footage shows the door open at the time.
"We accept this was never a case with an intention to kill."
The prosecution's case was that he did intend to cause serious harm to Mr Cateley.
Mr Steer said that, after "careful consideration", the prosecution had accepted the plea of guilty to manslaughter.
Judge Michael Henshell told Mr Steer: "I am absolutely satisfied the facts of this tragic matter are properly reflected by the plea you have accepted.
"The sentence will inevitably be custodial."
McNulty was remanded in custody until his sentencing on 7 April.