Lewis Hamilton has a new purpose at the beach ... rep Justin Bieber to a T (shirtless).
The Formula One race car driver was out Sunday on a beach in Barbados, where he was rockin' Bieber's Purpose Tour shorts ... the same ones the Biebs was seen in himself last week.
From the looks of these pics ... Lewis must've thought they were gym shorts, 'cause he's in full beach action mode ... catching footballs and hitting the water.
One thing's for sure -- he's got Bieber's look down lock, stock and barrel .