Stithians were unbeaten in nine matches before their visit to Bitton Park – and what made the result even more remarkable is that Teignmouth finished the game with 13 players after two players were shown red cards.
The hosts' were 20-3 to the good front before the boys from Cornwall started to look like a team that their third placed league position suggested.
Teigns' captain Colin Aldworth opened the scoring with a try in the corner, which Dan Force, who went on to give an outstanding man of the match performance, failed to convert.
The remainder of the half was action-packed. Hooker Andy Webber broke down the wing to score; centre Byron Woods was awarded a penalty try as he was high-tackled as he went to ground the ball, and Matt Moses was sent off for throwing a punch. Force also kicked another penalty.
The visitors, playing with a blustery wind behind them, did not take the advantage of their extra man, which was further increased when Teigns' scrum half Steffan Walker was sent off along with Stithians' number seven Tom Watts trading punches.
It was Teignmouth who increased their score with well executed tries from Will Sowden and Nick Andrews – both running from deep in their own half to score. Force converted both and booted over two further penalties to take his points tally for the game to 15.
Tomorrow, Teignmouth are away to north Devon side Torrington, while the reserves entertain Ivybridge Thirds.