Chris Hughton's men were in control during the opening half and saw their efforts rewarded, first when Sebastien Bassong bundled in Robert Snodgrass' free-kick on eight minutes, then again as Anthony Pilkington picked up Bradley Johnson's pinpoint long pass before shrugging off Carlos Cuellar to fire home.
Sunderland snatched one back on the stroke of half-time to swing the momentum in their favour ahead of the break, with Craig Gardner driving the ball past Mark Bunn from the edge of the box after some tidy work from Adam Johnson on the left, but they were unable to find another despite dominating the second half.
The hosts dominated the opening exchanges and looked much sharper in possession, with Sunderland defender Matthew Kilgallon cautioned by referee Phil Dowd after just three minutes for tugging at Norwich skipper Grant Holt as he turned past him.
Another free-kick conceded five minutes later led to the opening goal as Snodgrass' set-piece was flicked on by Bradley Johnson, the ball taking a deflection off the arm of Cuellar before being bundled home from close range by Bassong, with the borderline offside decision going in Norwich's favour.
Sunderland finally tested Mark Bunn in the 28th minute as Sebastian Larsson pulled a corner back to the edge of the box to Danny Rose, who fired in a low effort that the Norwich goalkeeper did well to keep hold of. The game became a little scrappy as the half progressed but the Canaries would double their lead eight minutes before the break.
Bradley Johnson played a through ball into the run of Pilkington, who was played onside by Kilgallon, and the winger ran through on goal before rounding Cuellar and coolly slotting past Simon Mignolet.
With just one minute remaining before half-time, Sunderland hauled themselves back into the game. Adam Johnson skipped down the left flank and pulled the ball across to Gardner who arrowed a low effort past Bunn, although the former Blackburn goalkeeper may feel he could have kept it out.
Sunderland boss Martin O'Neill introduced striker Connor Wickham at half-time, with the injured Steven Fletcher making way, and the visitors started the second half brightly, with only a clearance from Ryan Bennett stopping Wickham from tapping home to make an immediate impact.
Where Norwich had looked calm and assured in possession for the majority of the first half, Gardner's goal seemed to knock them off their stride and they played a number of lacklustre passes in the early stages of the second 45 minutes.
Sunderland came close as Gardner and Sessegnon had chances, while Wickham saw his would-be goal flagged offside, and with his side still struggling to contain the visitors Hughton introduced Elliott Bennett from the bench in place of Snodgrass to offer more pace in attack.
O'Neill threw on Fraizer Campbell and David Vaughan in the closing stages but Norwich held on to extend their unbeaten league run to eight games and move six points ahead of Sunderland in the table.
The defeat piles more pressure on Martin O'Neill's Black Cats side, who remain on the brink of the Premier League drop zone, just a point from safety.
|Norwich City||Team Statistics||Sunderland|
|2||1st Half Goals||1|
|3||Shots on Target||5|
|2||Shots off Target||10|
|55.7||1st Half Poss.||44.3|
|42.8||2nd Half Poss.||57.2|