Police officers who quizzed Kieran Cochrane about the attack found blood from the victim on one of his trainers.
Cochrane, of Birrens Road, Motherwell, appeared at Hamilton Sheriff Court on Thursday (June 9) on his 28th birthday.
He admitted punching, kicking and stabbing Kaine Jones at a house in Silverburn Cresent in March 2018.
The court heard that Cochrane and a number of other individuals had gone to the house.
An argument broke out and Mr Jones was stabbed, suffering a chest wound that required four stitches.
Cochrane said the knife belonged to the victim and they had wrestled over it on the floor - a claim the Crown didn't contest.
When police officers traced Cochrane they took him to hospital for treatment to a finger injury.
Blood on his trainers was found to be his and the victim's. Bloodstains on the driveway of the house where the attack happened were from Cochrane's injury.
No reason was given for the case taking so long to reach court.
Defence agent Diarmid Bruce said Cochrane's memory of events had been affected by drink.
The solicitor stated: "He is disgusted to find himself in this position.
"The consequence of this incident was that he stopped drinking. He barely leaves the house now. He is a young man who is deemed vulnerable due to learning difficulties.
"Given this and the passage of time, I submit there are options other than custody."
Sheriff Linda Nicolson told Cochrane: "It's a serious offence that in many instances would result in a jail sentence.
"But there doesn't appear to be a pattern of offending and there has been a change in your circumstances since."
Cochrane was put under supervision for 12 months and ordered to do 300 hours of unpaid community work within one year. He will also be electronically tagged for 163 days, meaning he can't leave his home between 7pm and 7am each day.