A victim of the Borough Market attack swung his skateboard at the terrorists as police desperately tried to help the injured, an inquest has heard.
Ignacio Echeverria, 39, was cycling with two friends on June 3 2017 when he came across Constable Wayne Marques and Constable Charlie Guenigault.
The officers had stepped in help Oliver Downing and Marie Bondeville, who were among people cut down by three knifemen near Borough Market.
Mr Echeverria, an HSBC financial crime analyst, ran across to help and swung his board at one of the killers but was knocked to the ground by Rachid Redouane, the inquest was told.
Detective Superintendent Rebecca Riggs told the Old Bailey: “Ignacio got off his bike and ran across to where the two officers were to assist the two officers.
“He had taken his board from his rucksack and swung at the attackers and managed to hit them. (Rachid) Redouane retaliated, causing him to fall on the ground.
“The attackers then set upon him on the ground.”
Counsel to the coroner Jonathan Hough QC said: “It was a brief but furious assault.”
Mr Echeverria was the last of eight fatalities around London Bridge and Borough Market in an attack which also left 48 people seriously injured.
The other victims were Christine Archibald, 30, Xavier Thomas, 45, Alexandre Pigeard, 26, Sara Zelenak, 21, Kirsty Boden, 28, Sebastien Belanger, 36, and James McMullan, 32.
An inquest into their deaths heard Khuram Butt, 27, Redouane, 30, and Youssef Zaghba, 22, ploughed into pedestrians on the bridge then attacked random members of the public with pink 12in ceramic knives.
Zaghba and Butt discarded their jackets to reveal fake suicide vests before the terrorists confronted unarmed police officers shouting “Allahu Akbar”.
The onslaught came to an end after less than 10 minutes when the attackers were shot by City of London Police marksmen.
Neil McLelland, who was looking out of the window of the nearby Wheatsheaf pub, was hit in the head by a bullet and fell to the ground, while five other people were injured by shrapnel.
Other armed officers arrived on the scene, and Det Sgt Riggs said: “Believing that they (the attackers) were wearing improvised explosive devices they withdrew.
“They could see that the attackers were still moving. They believed they were going to activate the explosive devices they were wearing and they fired a number of shots.”
Mr Hough said the officers then put “themselves in harm’s way” to evacuate the pub, taking Mr McLelland, who survived his injuries, and others to safety.