A fight in a pub on Origin night has led to an 18-year-old being fatally shot in Sydney’s west and a 21-year-old being charged with murder.

A pub fight on State of Origin night led to an 18-year-old man being gunned down on a western Sydney street, police allege.

Matthew James Perry, 21, is accused of fatally shooting Jed Coates in the neck on Wednesday night after they’d both spent the evening watching NSW wrap up the Origin series with separate groups of friends at the Colyton Hotel.

Less than an hour after the full time siren, Coates was dead.

Neighbours living in Nevada Avenue, Colyton, reported hearing an argument in the street not long before police and paramedics arrived about 11pm. They tried to revive the young man, who reportedly worked as a carpenter.

He was taken to Westmead Hospital but died soon after.

Police arrested Perry, a panel beater, at his home on the same street just after 3am.

He was charged with murder and refused bail at Mount Druitt Local Court on Thursday morning.

Court documents say Mr Coates encountered Perry, who went to the same high school as him, at the Colyton Hotel while drinking and watching the Origin match with a mate.

They were kicked out of the pub after allegedly getting into a fight with Perry and his friends.

When Perry took a taxi home shortly afterwards, Mr Coates and his friend were waiting for him at the end of his street with Mr Coates allegedly armed with a shovel.

According to the documents, Mr Coates yelled “shoot me, shoot me”, before Perry shot him with a rifle just below the right side of his neck.

He then ran away after failing to find the cartridge in the dark.

Homicide detectives lined Nevada Avenue with police tape and conducted an extensive search of one of its houses and a car parked outside.

Mr Coates’ best mate Dean White watched on with another friend on Thursday morning, the pair holding back tears as they hugged each other.

Mr White said he’d decided to give the pub a miss and watch the game at home. He learned about what happened through phone calls from other friends.

“I didn’t think it was real until we saw the news this morning,” he told AAP.

Mr Coates’ family were informed of his death overnight.

The 18-year-old’s twin brother, Sam, paid tribute to his sibling online.

“Rip Jed my brother my twin your a king in my eyes love you bro.”

Friends of the young man are posting messages on Facebook.

“Rest in peace. You we a good kid. Didn’t deserve this,” read one.

Perry will appear at Penrith Local Court in August.