A man was caught on CCTV as he stabbed his victim four times in the stomach.
David Holmes, 25, launched the attack in Duntocher, West Dunbartonshire, on 29 April, after Gary Haggerty punched him to the ground.
He also struck have-a-go hero Richard Buchanan with the knife on Craigielea Road as he tried to disarm him.
Holmes was convicted of the attempted murder of Mr Haggerty and also of assaulting Mr Buchanan with a knife.
'Weak and dazed'
Prosecutor Patricia Comiskey said: "After David Holmes was disarmed of the knife, he left and then returned with a second knife.
"His victim, Mr Haggerty, said he was weak and dazed and thought he was going to die."
A jury at the High Court in Glasgow was shown video footage of the murder attempt on Mr Haggerty.
Judge Lady Scott deferred sentence on Holmes, who is a prisoner at HMP Greenock, until next month when she will sentence him.
She also ordered a report to assess the risk he poses to the public.
The court heard that Holmes, who admitted possession of a knife, has six previous convictions for violence.