Goals from Sebastien Bassong and Anthony Pilkington secured a fourth successive home win for Norwich City at Carrow Road, as Sunderland's second-half fightback was not enough to make up for a meek opening 45 minutes.
Craig Gardner got one back just before the break but the visitors squandered chances to draw level as the pressure increased on Martin O'Neill.
The Canaries came into the match on a seven-game unbeaten streak, while the Black Cats were sitting just above the relegation zone with just one win in eight. This contrast in fortunes was evident from the beginning, as the hosts were far confident than their guests, who invited pressure upon themselves early.
It was no surprise when the hosts took the lead on eight minutes, when a fine piece of interplay between the influential Wes Hoolahan and Steven Whittaker resulted in a free kick on the right hand side of the box thanks to a clumsy challenge by Danny Rose.
Robert Snodgrass duly stepped up and delivered a wicked ball into the area with his left foot, which deflected off Carlos Cuellar to leave Bassong to gleefully tap home from two yards out with Simon Mignolet stranded.
Spurred on by a raucous home crowd, Norwich continued to dominate possession and were rewarded with a second goal after a fine passage of patient passing play.
Bradley Johnson played a precise long ball over the top to find Pilkington just onside and racing through on goal. The winger made the finish look easy, jinking inside Cuellar's challenge before striking the ball emphatically into the far post for his second goal in successive home games.
Things were looking ominous for O'Neill's men but they were thrown a lifeline when Gardner's long-range effort squirmed through the hands of Mark Bunn and into the far post to halve the deficit just before the break.
Former Ipswich Town striker Connor Wickham replaced the injured Steven Fletcher at half-time, entering the field to a chorus of boos from the home crowd.
The 19-year-old almost silenced the Canaries faithful within a couple of minutes, as Stephane Sessegnon's driven cross was brilliantly blocked by Ryan Bennett with the England Under-21s international lurking inside the six-yard box.
Sunderland were playing with more urgency after half-time and should have pulled level when Gardner's swerving free kick from 30 yards came back off the post to the feet of Matthew Kilgallon, who somehow managed to scoop the ball over the bar with the goal gaping.
The Mackems came close twice within the next few minutes, Javier Garrido first clearing Gardner's shot off the line after Bunn's weak punch from a corner, before the goalkeeper redeemed himself with a fine save from Sessegnon after the Benin international was put through by Rose.
The offside flag denied Wickham a dream goal when he was on hand to tap in Bunn's fumble of Rose's stinging volley after a half-cleared corner, as the guests continued to press.
However, despite their second-half renaissance, the visitors were unable to get that crucial second goal and left Carrow Road empty-handed, with O'Neill surely wondering why it took his players 45 minutes to show any ambition.