Ian McElwain, 46, was yesterday convicted of stealing money and jewellery from Charles Mulholland's flat at Taylor Place in Townhead, Glasgow, on June 21, 2013.
Slightly built Mr Mulholland felled the robber with a single punch after finding him hiding in his living room. The jury heard how he cornered him "like a lion tamer" with a chair after the man threatened to "cut him". Mr Mulholland likened himself to a "Terrier fighting a Rottweiler".
Speaking outside court about the incident, Mr Mulholland said he spotted McElwain in his living room rifling through drawers when he returned from the toilet.
He said: "I never thought about being scared - I just punched him in the stomach."
McElwain had a gold wedding ring and watch belonging to Mr Mulholland's late wife.
The pensioner said: "I wasn't bothered about the money, it was the ring and watch. I can't put it into words, there's nothing that can bring them back."
Sheriff Paul Crozier told McElwain: "It is quite frankly despicable an 82-year-old person cannot be left to enjoy his own home in safety."