Holders Berkhamsted relinquished their hold on the St Mary’s Cup as Oxhey Jets raced into a 3-0 lead in the first quarter of the game to move through to the quarter-finals.
Lee Armitt broke the deadlock in the fifth minute, before Luke Beardsworth doubled the visitors’ lead minutes later.
Berko striker Connor Calcutt blasted over the bar, but Armitt lobbed his second goal to make it 3-0.
The Comrades were given hope when Frankie Jowle pulled a goal back before the interval, but the Jets held firm after the break to book their place in the last-eight.