Cops are now appealing for information following the horror at 7.20pm on August 22 - and are still hunting the gunman.
They confirmed the victims were rushed to hospital for treatment but none of their conditions were life threatening.
A Metropolitan Police spokesperson said: "Officers are investigating a shooting in Lambeth on Thursday, 22 August.
"Police were called to Morrish Road, SW2 at 21.33hrs and found one male aged 17, and a two 22-year-old men with gunshot injuries.