Farke, who fielded five debutants including winger Roberts and 18-year-old striker Adam Idah, became increasingly agitated as the game slipped away and was shown a second-half yellow card for his protestations by referee John Busby.

After dominating the early exchanges, Norwich were shocked with 17 minutes on the clock.

Town forward Lubala received the ball back from Nathan Ferguson following a short left-wing corner and his whipped delivery was inadvertently deflected beyond Norwich goalkeeper Ralf Fahrmann by Republic of Ireland Under-21 international Idah.

Both sides were forced into substitutions after a nasty collision left Norwich defender Timm Klose and Crawley's Panutche Camara struggling, before City almost equalised when Roberts clipped the left post.

Norwich were again denied by the frame of the goal on the hour mark after Buendia rattled the crossbar.

Despite their surprise lead, Crawley continued to show attacking intent and striker Ollie Palmer, who earned a start by scoring twice as a substitute in the weekend win at Leyton Orient, would have doubled the lead had it not been for a smart stop from Fahrmann, while Ferguson later curled narrowly wide.

Crawley's on-loan German goalkeeper Michael Luyambula had little to do in the second half and – after Mario Vrancic headed wide from an inviting Buendia free-kick four minutes from time – the hosts hung on for a famous victory.