Gerrard's six co-defendants earlier pleaded guilty to being involved in the bar brawl on Dec. 29 in a town near the northwestern city of Liverpool, leaving the 29-year-old England midfielder to stand trial on charges related to the fight.
Prosecutor David Turner QC told a Liverpool court 34-year-old Marcus McGee, in charge of music for the night at Southport's Lounge Bar, refused to let Gerrard take control of a CD player, the Press Association reported.
The court was shown security camera footage of Gerrard talking to McGee before one of Gerrard's co-defendants elbowed the businessman.
"Within seconds, Steven Gerrard joined in the attack with a succession of well aimed uppercut punches delivered with the style and speed of a professional boxer rather than a professional footballer," Turner told the court.
The England international was arrested on the night, a day after he scored twice in a 5-1 win at Newcastle United, and later pleaded not guilty to a charge of affray.
The jury was told Gerrard had admitted hitting McGee but said he was acting in self defence, unaware the businessman had already been struck.
"If you consider Steven Gerrard was or even may have been acting in self defence you will acquit," Turner said.
"But we say on this occasion Steven Gerrard's fists, not his feet, did the talking."
Gerrard signed a two-year contract extension in April that will keep him at Anfield until at least 2013, and Liverpool manager Rafael Benitez has said the club are fully behind their captain.
The case resumes on Wednesday.
