Phil Mulryne swept home a spectacular late winner just four minutes after coming on as a substitute for the Canaries, who move two points clear of West Brom at the top of the table with this victory.
But the breakthrough goal came with a large assist from referee Neale Barry, who got in the way of a Dean Gordon clearance to key up Mulryne's winner.
A second defeat in the space of two days left Reading shy of the play-off places and with games fast running out. But defeat was rough off Steve Coppell's side after they had played their part in an entertaining clash.
The visitors were the first to threaten though, Darren Huckerby running on to a long punt forward from goalkeeper Robert Green and hitting a low shot that Jamie Ashdown did well to push onto a post.
Green was also in good early form at the other end, pushing a Steve Sidwell shot around the post after Nicky Forster had played the midfielder in.
Forster and winger John Salako both saw headers fly straight at Green and defender Graeme Murty hit a fierce shot which again failed to force the keeper to move his feet but Reading could not find a way through.
Having weathered something of a first-half storm. Norwich turned up the heat after the break and went into search of the victory that would help end their top-flight exile.
Ashdown blocked well at the feet of Damien Francis and, from the resulting corner, Malky Mackay's header was hacked off the line by Salako.
The lively Huckerby had two penalty claims waved away by Barry, but the man in the middle ultimately did the visitors a big favour in the closing stages.
Having twice intervened in the game already, the hapless Barry got in the way of the ball for the third time with just four minutes left and Mulryne gratefully accepted the chance to sweep a shot beyond the dive of Ashdown.