Fakenham suffered a narrow defeat at Little Melton after finishing the game with just 13 men.
Jack Powell-Thorne was red carded for an unsafe tackle early on but it was the visitors who took the lead through a Tom Bane-Young penalty.
At half-time the score remained the same, with Crusaders having had probably some 70 percent of possession but failing to take their chances.
The hosts finally scored a well deserved try 15 minutes into the second half through Lewis Kenworthy and Ryan Harris' kick made it 7-3.
Fakenham responded well, piling on the pressure, and Bane-Young's arm appeared from a mass of bodies to get a try which he duly converted.
Crusaders hit back and Harris ran in a try the short distance from the base of the scrum to score just before the whistle blew to win it, with the same player converting.
Bane-Young was red carded just before the whistle for indiscipline to complete a frustrating day for the visitors.
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