Jermaine Johnson's deflected shot earned a deserved away victory for Sheffield Wednesday and left Norwich a point clear of the relegation zone.
The Owls took the lead when Johnson's strike deflected off defender Jon Otsemobor early in the second half.
An anxious Carrow Road crowd saw David Mooney's 84th-minute equaliser ruled out after a foul in the build-up.
But Wednesday clung on for the three points after defender Tommy Spurr was sent off for his second yellow card.
Norwich manager Bryan Gunn:
"To be honest we didn't play well in the first half, while at the same time Sheffield Wednesday played some relaxed football.
"After the break I didn't think there was much in it but unfortunately they've had a shot which has taken a deflection to beat our goalkeeper.
"There was no ranting and raving in the dressing room afterwards, because we need the players to believe that we can get enough points between now and the end of the season to ensure our safety."
Sheffield Wednesday boss Brian Laws:
"I don't think anyone would disagree that we deserved to win.
"We have been exceptionally good in our last four away games and deserved to win all of them in my opinion.
"Today was no different and this time we got our just rewards. We dominated the first half, passed and moved really well and had 10 strikes on goal."
Norwich: Marshall, Otsemobor, Shackell, Doherty, Bertrand, Croft (Lee 68), Clingan, Lappin, Carney (Smith 82), Gow (McDonald 82), Mooney.
Subs Not Used: Nelson, Drury.
Booked: Mooney.
Sheff Wed: Grant, Buxton, Hinds, Wood, Spurr, Varney, McAllister, Potter, Johnson (Beevers 88), Tudgay, Jeffers (Sodje 82).
Subs Not Used: Esajas, O'Connor, Simek.
Sent Off: Spurr (89).
Booked: Wood, Spurr.
Att: 25,385
Ref: Mike Russell (Hertfordshire).
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