Harry Smith smashed a quickfire 60 off 39 balls as Great & Little Tew beat Chesham by four wickets at home in the second round of the HCPL Twenty 20.
They now face Banbury or Tring in the next round.
After losing a wicket in the first over, Chesham reached 153 from their 20 overs.
Skipper Andy Harris took 3-32 in his four overs.
An 86-run opening partnership between Smith and Joe White (37) got Tew off to a solid start before they passed the victory target with seven balls to spare.