The 29-year-old officer was off-duty when he was awoken by a disturbance near his home in Barnes High Street, SW13, at about 3.30am on Friday, 31 May.
He realised a jewellers’ shop window had been smashed and that suspects were attempting to break in.
Acting instantly, he ran out into the street in just his boxers – he challenged them and a pick axe was thrown at him.
It narrowly missed him and he picked it up and ran at the suspects to stop them further breaking into the shop.
The four suspects managed to escape on mopeds but left behind a number of weapons including a pick-axe, sledgehammer and a chisel.
The shop window was damaged but the suspects did not manage to break in and steal any property.
The officer cut his foot on broken glass but was not otherwise injured.