Hambledon are just three wins away from Lord's after a stunning triumph at Ridge Meadow on Sunday.
The Dons defeated Truro-based outfit Stithians by 41 runs in the last 32 of the ECB National Village Knockout.
Skipper Dan Hewitt struck 52 as his side posted 222 for eight in their 40 overs.
Paul Vickers and James Scutt both weighed in with 32 before the hosts restricted their Cornwall opponents to 181 for nine.
Mark Le-Clercq and Rhidian Chapman both grabbed three wickets, while James Atkinson took two as the Dons booked their place in the last 16.
Hewitt's men with now play Wraysbury on July 14 with a place in the quarter-finals up for grabs.