Mr Ali is alleged to have threatened Mr Stokes' England teammate Alex Hales with a bottle during the altercation, while Mr Hale broke off a metal pole from a nearby road sign after being allegedly knocked out by Mr Stokes.
"The individual seemed to be the main aggressor or was progressing forward trying to get to another individual", Mr. Spure told the court.
Stokes, the England cricketer who is standing trial for affray alongside Ryan Ali and Ryan Hale, was also described as feeling "vulnerable and frightened" as the incident unfolded and claimed that, having seen at least one bottle used in the brawl, feared his opponents had "demonstrated a willingness to use weapons in attacking people".
Stokes and several other England players had gone to Mbargo to celebrate a one-day global win over the West Indies last September.
"These men were speaking to the gay guys in what I would call a harsh and abusive way", the statement said.
"One of the guys responded - he said "shut up or I'll bottle you" in an aggressive tone to me".
All three defendants deny the charge.
"I decided at this point matters had become too serious to ignore and that I had to intervene to stop Ryan Ali", Stokes told police. I took exception and said "leave it out".
Stokes' police interview at the time lasted 21 minutes, and involved two handwritten statements.More news: Smash Ultimate Gets New Modes "Squad Strike" and "Smashdown"
More news: China continues 'fair and lawful' business in Iran, despite US sanctions
More news: The Stands : James Anderson's painful golf swing
Mr Spure described seeing Stokes punch Ali, who was trying to get away, with a "clenched fist" in the road.
"I felt the need to defend myself". Yesterday, the court heard Stokes bullied the gay revellers, throwing a cigarette at one and making mocking gestures at them. "I can only guess I thought I was going to be attacked".
In a statement, Mr Spure said he had tried to separate Mr Stokes and Mr Ali, with the others continuing their behaviour behind him.
"I chose to intervene and asked Ryan Ali and Ryan Hale to stop abusing Kai and William".
Cunningham said he did not step in until Stokes flicked a cigarette butt at the men.
Mr Stokes, of Castle Eden, Durham, was arrested in the early hours along with Mr Ali, of Bristol, and Mr Hale, of Westbury-on-Trym, Bristol.
The prosecution has read medical evidence of injuries sustained by Ali and Hale. He was subsequently taken to hospital by ambulance and diagnosed with a fractured eye socket.
Ryan Hale (L) arrives at Bristol Crown Court on August 6, 2018 in Bristol, England.