The sergeant in charge of Pc Keith Blakelock's unit has described the "absolutely terrifying" moment they came under attack by a mob armed with iron bars and a machete.
David Pengelly led his team of 10 officers to protect firefighters tackling a blaze at the Broadwater Farm estate.
When they arrived, he said: "There were lines of officers with shields. There were missiles being thrown. It was a scene of considerable rioting."
As the team went with firefighters to the blaze, it was Pc Blakelock who suggested someone should stay by the stairwell to protect their exit, which he and another officer then did.
Mr Pengelly said: "I saw a group of youths. My eye was drawn to youths who were running underneath us. A group appeared at the far side of the level we were on from an entrance of some sort."
One rioter he noticed had muslin covering his face, with eye holes cut into it, he said.
Mr Pengelly raised his visor to shout at the crowd that they were just there to "protect the firemen".
He went on: "There was something perhaps of a dramatic pause. I do not know the reason. Then another group appeared slightly to the right from an unknown point to me.
"There was no time to reflect as the second group immediately starting throwing items at us - bottles, bricks, I believe mainly."
Some of the youths then started to run around to "effectively out flank us and cut off our retreat" so Mr Pengelly gave the order to retreat down the stairs to the ground level.
"Obviously at this point, the rioters were right with us hammering on the shields. It was an absolutely terrifying scenario.
"As we retreated down the stairway there were people with iron bars and at least one with a machete, effectively trying to chop the shields to bits. The retreat to ground level was just a continuing nightmare."
More top news
Ministry of Defence investigating allegations that members of the British Army shouted sexist abuse watching England Women football team.
The US space agency NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet.
Comedian Peter Kay has said he is "thrilled" to star in a adaptation of broadcaster Danny Baker's autobiography.