A group of youths traded weapons before violently attacking a couple and stabbing the man with a Rambo knife, leaving his intestines sticking out.
Corey-Jay Thomas, 18, and Jay Jones, 22, attacked couple Justin Jenkins and Gemma Maidment in Caerphilly town centre during the early hours of 14 May.
Mr Jenkins and Ms Maidment were in the shopping precinct before being approached by a third attacker.
Jessie Watson, 19, walked up to the couple and accused them of "having beef" to which Ms Maidment responded "Leave it" and continued walking. The couple were then pursued by the group.
"What started as a verbal altercation led to violence," said prosecutor Alex Greenwood.
Jones was initially armed with a Rambo knife before trading his weapon with Thomas who had a pen knife.
CCTV footage of the incident depicted the group chasing Mr Jenkins who tried to defend Ms Maidment. The male victim was stabbed with the Rambo knife by Thomas, causing a 5cm wound to his abdomen and resulting in his intestines protruding through the injury.
Mr Jenkins later required five blood transfusions as a result of the attack, a court heard.
Ms Maidment was brought to the floor by Watson who punched her repeatedly before Jones knocked her unconscious by kicking her in the face. Jones then grabbed her handbag and ran away with Watson.
The defendants discarded of the weapon used to stab Mr Jenkins in a nearby garden path as they returned to Jones' mother's house.
Jones, Thomas and Watson were identified and arrested.
Corey-Jay Thomas, of Pwllypant, pleaded guilty to wounding with intent and was sentenced to six years of detention in a young offenders' institute.
Jessie Watson, of Lansbury Park, pleaded guilty to inflicting grievous bodily harm and was sentenced to a two-year community order and 180 hours unpaid work.
Jay Jones, of Blackwood, pleaded guilty to causing grievous bodily harm with intent and possession of a bladed article and was sentenced to four years imprisonment. He was also made subject to a restraining order for six years.
"You kicked (Ms Maidment) to the head with terrifying force and rendered her unconscious. It was an act of staggering cowardice by you," said Judge Daniel Williams during the sentencing.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know…