Peter Buck was arrested shortly after touchdown
Captain Tom Payne described how Mr Buck wrought havoc on the Seattle-to-Heathrow flight and mocked efforts to bring him under control.
The captain decided to issue a warning card amid allegations that a crew member had been assaulted, a hostess trolley overturned, and a knife confiscated from Mr Buck.
Mr Buck denies one charge of being drunk on an aircraft last April, two counts of common assault involving cabin services director Mario Agius and stewardess Holly Ward, and one charge of damaging British Airways crockery.
Mr Payne told west London's Isleworth Crown Court: "I had a conversation with the crew to decide the best course of events at that time, taking into account where we were over the ocean and how long we had to fly."
"We could divert to the nearest airport, drop him off or press on and call the police.
"I decided to press on."
Mr Buck was arrested when police boarded the plane shortly after touchdown.
Mr Payne said the 45-year-old's actions had created mayhem on the 10-hour flight.
Midway through the journey, the captain entered the first-class cabin to find him arguing with Mr Agius in the galley.
"He had a bottle of wine in his hand," Mr Payne told the court.
"Mr Agius said he could not have it and there was an altercation where Mr Agius took it from him."
As Mr Buck's behaviour continued to worsen, the captain presented him with a so-called "yellow card" warning him to behave.
"But when I served the document he took it, tore it into pieces and dropped them on the floor," Mr Payne said
"It was as though what I had done was irrelevant.
"He was just standing there in front of me with very little expression, trying to ignore me, as if I had not done anything."
Other witnesses said earlier that Mr Buck had sworn at Mr Payne, saying: "You are just a captain and I am REM."
But the captain said he had been unable to understand the insult because the star's speech was so slurred.
"He sounded like someone from Texas in America - with a very slow drawl," Mr Payne told the jury.