The woman told Leeds Crown Court that the incident outside Scarborough Town Hall lasted “10-to-15 seconds”.
“It all happened very fast,” she said under cross-examination by defence counsel.
The young woman, who was giving evidence via video link, said she couldn’t pick out any of the men involved in the stabbing because it was dark.
She said she saw “five or six lads fighting” during the fatal incident in the early hours of October 20 2019.
The woman, who had been with Mr Robinson that night, said she couldn’t see the attackers’ faces because they all had their hoods up and it was dark, but she did hear one of the gang shouting, “You’re a pussy” at Mr Robinson.
She saw him “begin to sway in the road”, take a few steps back and then collapse on the edge of the pavement outside the gardens. She then shouted for someone to call an ambulance.
Clive Stockwell, for Stevie Low, asked the witness: “Are you saying you don’t know who did what in that commotion because it was dark?”
“Yes,” replied the woman.
“So, you did not see Stevie Low amongst that commotion?”
“No, I didn’t see anyone,” replied the witness.
The woman was giving evidence on day two of the trial, which is expected to last four weeks.
Dawid Goral, 21, Callon Brass, 22, Kieran Watkinson, 19, and Stevie Low, 23, are accused of murdering 26-year-old Mr Robinson, who was knifed to death near the Queen Victoria statue in the gardens outside the town hall.
A fifth Scarborough man, 19-year-old Stefan Selvage, of Colescliffe Road, has already admitted murder after CCTV footage showed him following Mr Robinson into the park on a bike, before jumping off and plunging a blade into his back.
The harrowing footage, played in court on the first day of the trial, showed that at least two of the attackers - all wearing dark clothes and hoodies - were wielding long-bladed knives, including a machete.
Mr Robinson staggered back towards the entrance to the gardens but collapsed on the pavement in a pool of blood. His friends and others rushed to his aid and an ambulance was called as the gang ran off.
Paramedics arrived and Mr Robinson, who suffered an 11-inch-deep wound to his lower back, was taken to hospital by ambulance after suffering “catastrophic” bleeding.
Surgeons fought to save his life during emergency surgery, but Mr Robinson died just before 5am – about three hours after the attack.
A post-mortem found that the cause of death was a single stab wound which had severed a major artery and resulted in “massive” blood loss.
Brass, of Eastborough, Goral, of Durham Street, Low, of Longwestgate, and Watkinson, of Endcliff Crescent, all denied murder following their arrests shortly after the incident.
Prosecutor Taahir Khan QC said the five men were loitering outside the town hall in the early hours of the morning, apparently waiting for Robinson, who was talking to two friends at the other end of St Nicholas Street.
Mr Khan said it was the Crown’s case that the fatal stabbing was not the work of Selvage alone and that others in the gang had taken part in a “joint” attack.
Another witness, a man named in court who was socialising with friends after work, said he too heard a “commotion” coming from the park.
He saw a man with a blue top emerging from the park with his hood up.
“This male came to (the witness’s) attention because he was carrying something in his hand,” added Mr Khan.
“It appeared to be a bladed article about 25cm long.
“The actual (proven) stabbing was carried out by Stefan Selvage with what we suggest was a machete, but he wasn’t the only person armed with a knife at this time.”
Mr Khan said at least one other man was brandishing a “long-bladed weapon” and, according to the male witness’s description, the “overwhelming likelihood” was that it was Dawid Goral.
He said it appeared that the gang were “wallowing (in) or celebrating” what they had done to Mr Robinson.
The court heard that in the hours leading up to the attack, the five suspects had been at a drug-and- alcohol-fuelled party at a flat on North Marine Road where knives were brandished and cocaine was consumed, weighed and bagged up while rap or Grime music blared in the background.
Two of the suspects, Watkinson and Low, made searches for Mr Robinson’s Facebook profile so he could be “targeted” by other members of the gang, said Mr Khan.
The five men left the flat to go into the town centre about 20 minutes before the fatal stabbing. Before leaving the flat, Watkinson sent a text message to a female acquaintance saying: “Wow, off to stab up. Heads off (sic) in town now. Off on a move. Big cash.”
The trial continues.