Before Marco Deng allegedly stabbed Machar Kot, he was angry the Melbourne man had apparently called him a snitch.
Deng didn't hear the jibe from Mr Kot but learned of it through social media posts his friends were talking about.
In the early hours of June 22, 2020, Deng met Mr Kot, apparently trying to source Xanax.
Deng is standing trial for murder in Victoria's Supreme Court where prosecutors have claimed the Xanax purchase was just a ruse so Deng could fight Mr Kot.
Deng has pleaded not guilty.
He told police after the stabbing that he was angry about the snitch comment.
"Not to the max, but I was annoyed so I just went and fought him," Deng told police.
Deng and his friends went to a hotel in the Melbourne CBD where they had arranged to meet Mr Kot and his friends.
Deng ushered Mr Kot away from his friends and around a corner. He confronted Mr Kot about the snitch comment.
He allegedly punched Mr Kot in the head and was struck himself in retaliation.
"It seemed to have been a better punch because it knocked Mr Deng to the ground," prosecutor Mark Gibson said.
The pair fought before Deng allegedly armed himself with a knife,.
Deng allegedly pursued Mr Kot around Market Street in the CBD and to the Oaks on Market hotel.
Mr Kot tried to seek refuge in the hotel foyer but was pursued by Deng and cornered, Mr Gibson said.
He lunged at Mr Kot and stabbed him in the torso, the court heard. Mr Kot went into cardiac arrest and died.
There were attempts to wrestle the knife from Deng before he fled with his friends, spotted by a security guard who heard screams.
Deng was arrested several days later after seeking medical treatment for injuries.
He denied having a weapon and said he couldn't explain how Mr Kot was stabbed.
The trial before Justice Mandy Fox is set to continue on Wednesday when jurors will be shown footage of the incident.