The troops were surrounded by approximately 50 ISIS militants yesterday close to Mosul in Northern Iraq as they had just withdrawn from an intelligence gathering mission, according to the Daily Star.
In the ambush, soldiers fatally shot several militants before their ammunition ran out and they were forced to use their guns as battering rams, knives, wit and brute strength to defeat the enemy.
One man even drowned an ISIS fighter in a puddle before picking up a stone which he smashed into another man's face.
Sources told the Daily Star that they were convinced they were going to die in the battle, so they chose to 'go out fighting' in the hope that they would kill as many ISIS fighters as possible before they died.
One source told The Daily Star: 'The SAS unit was trapped in a small river bed. They did a quick ammo check and realised they had less that 10 bullets left between them.
'They knew that if they were captured they would be tortured and decapitated.
'Rather than die on their knees, they went for a soldier's death and charged the IS fighters who were moving along the river bed. They were screaming and swearing as they set about the terrorists.'
The soldiers then used everything at their disposal in the desperate fight for their lives.
Displaced civilians from Mosul's Old City, the last district in the hands of Islamic State militants, flee during fighting in western Mosul, Iraq on June 24
The source counted 32 dead ISIS fighters during the battle which lasted just over four hours.
By its bloody end, the source said the remaining enemy forces had fled and despite multiple injuries - including gunshot wounds - the SAS unit walked five miles where a Kurdish fighter met them and brought them back to their base.
Those same soldiers are reported to have returned to duty just two days later, apart from those who were shot.
A Ministry of Defence statement says that the RAF is continuing to support Iraqi forces in their effort to liberate western Mosul.
'While the operating environment in the city is very challenging, particularly given the closely-packed buildings, very narrow streets, and the density of the urban population, our aircrew have continued to deliver precision strikes in close support of Iraqi troops on the ground.
'Daesh’s current tactics, including the illegal use of civilians as human shields, and fighting from sites such as schools, hospitals, religious sites and civilian neighbourhoods, increases the risk to innocent life.
'While no military operations come without risk, particularly in dense urban environments and against such inhuman Daesh tactics, the RAF continues to take all steps necessary to minimise civilian casualties.'