A 78-year-old man killed a much younger burglar who broke into his London home — and was busted on suspicion of murder, authorities said.

The unidentified old-timer told Metropolitan Police he was snoozing with his wife when he heard noises, woke up, and discovered two intruders inside his Hither Green home a little after midnight on Wednesday, the Evening Standard reported.

One of the burglars, armed with a screwdriver, forced the older man into his kitchen while his partner rummaged upstairs.

Police said there was a violent struggle in the kitchen, where the geezer got the better of the 37-year-old robber — stabbing him in the chest.

The crook was later found collapsed on a nearby road and died at a hospital. Police couldn’t confirm whether he’d been stabbed with his own screwdriver, according to the Telegraph UK.

The homeowner suffered bruising to his arms and was arrested on suspicion of murder. He remains in custody.

The second suspected burglar — who police say was also armed — fled and is being hunted by the Homicide and Major Crime Command.