CHIPPENHAM’S relegation fears deepened as they could only muster a losing National Three South West bonus point at Allington Field.
Danny Thomas’ side are now 11 points adrift from safety, despite taking an 8-0 lead on Saturday.
They took the lead when second row Tom Knight touched down after a catch and drive from a lineout.
Full-back Sam Saunders, returning from injury, then landed a long-range penalty.
But Amersham got on the board when Chippenham lost possession and Jack Kenyon jinked his way over before half time.
The strengthening wind and worsening conditiuons made it a forwards-dominated encounter in the second half.
And Amersham grabbed the victory in the final moments as Stuart Day touched down and Ross Bugden’s conversion condemned the home side to an 11th straight league defeat.
REACTION TO CHIPPENHAM'S DEFEAT, PLUS MORE RUGBY REPORTS, REACTION & PICTURES IN THURSDAY'S GAZETTE & HERALD