Club headed into the game in red-hot form with 11 wins on the bounce, and they proved too strong from the off against their capital rivals.
Oskar Hirskyj-Douglas slipped over for a fourth-minute opener, Sam Morley with the extras for the visitors.
Hooker Billy Harding then rode a maul over for a remarkable 49th try of the season, and with Morley on target again and once more following a Tom Hughes try, it was 21-0 at half-time.
The former Esher fly-half extended the lead with an early second-half penalty.
Blackheath’s defence proved unbreachable until the 77th minute, when Jonny Law crossed and Josh Bellamy added the extras.
But it was always going to be merely a consolation, and Morley had the final word with a second three-pointer at the end.
*Picture from Blackheath RFC website
