An 85-year-old great grandfather, tackled would-be robbers wielding a sawn-off shotgun and hammers.

An 85-year-old great grandfather, who tackled would-be robbers wielding a sawn-off shotgun and hammers, has become an internet hit.

Denis O'Connor was at a Bar One Racing office in southern Ireland over the weekend when three robbers burst through the door. One jumped the counter and threatened the manager while another pointed a shotgun at O'Connor.

Surveillance cameras show O'Connor shoving a man from behind the counter. The robbers then ran off and the manager says he's grateful.

"I owe Denis a huge debt of gratitude. It was an incredible act of bravery from him," stated Tim Murphy, manager.

Irish police are still searching for the three suspects.