Leicester City's resurgence continued under the lights at the King Power Stadium thanks to goals from Islam Slimani and Jamie Vardy making it six wins in a row for Craig Shakespeare's men, while Sunderland looked more doomed than ever at the foot of the Premier League table after going six games without a goal.
The hosts opened the scoring through second-half substitute Slimani's close range header on 69 minutes, with their other substitute Marc Albrighton the man who provided the cross for the goal.
Albrighton got his second assist of the game on 78 minutes when he played in Vardy, who finished with power on his left foot to leave Jordan Pickford with no chance in the Sunderland goal for his tenth league goal of the season.
Leicester boss stuck with winning side
Craig Shakespeare opted to field the same side that ran out 2-0 winners against Stoke City on Sunday afternoon, while David Moyes made three changes after Sunderland succumbed to a 1-0 defeat at Watford on the same day.
Adnan Januzaj, John O'Shea and Darren Gibson were the men that dropped out of the side and in their place were Didier Ndong, Sebastian Larsson and captain Lee Cattermole, who has only just returned from his four month injury lay-off.
Leicester's recent resurgence has seen them win five games on the bounce in all competitions after title-winning manager Claudio Ranieri was replaced by Shakespeare, although the first-half display from both sides was an evenly matched contest.
Winger Demarai Gray was a threat for the Foxes throughout the opening 45 minutes, as he used his pace whenever possible to get the better of Billy Jones although his shooting from outside of the area was largely off the mark.
In the opening three minutes he showed why the Black Cats should remain wary of him for the rest of the match, as he easily outpaced Jones on the left flank before drilling a low cross towards Shinji Okazaki in the centre of the area, but the Japanese striker could only send his shot wide.
Gray's one strike that did test Pickford came at the end of the half when he cut inside Jones and drilled the ball towards the far corner of the Sunderland goal, only for the England Under-21 international keeper to send it around the post with a fingertip save.
The visitors showed some improvement from their recent defeat at Vicarage Road, with players getting forward in support of club top scorer Jermain Defoe on more occasions with Sunderland now entering must-win territory if they are to have any chance of staying up.
Ndong saw a shot from 20 yards drift a few yards wide of Kasper Schmeichel's left-hand post, while Defoe tried his luck from a similar distance only to see his effort lack the dip required to find the top corner of the Leicester net.
Second-half showing put Foxes on the road to victory
Defoe had a sight of goal 10 minutes into the second half after he picked up the rebound from Larsson's wide free-kick, but his volleyed effort was straight down the throat of Schmeichel who plucked the ball from the air with relative ease.
The hosts almost caught their opponents by surprise with a long throw from Christian Fuchs on 62 minutes as he directed the ball towards Robert Huth, but Pickford got down well to keep the German's header out.
Leicester broke the deadlock on 69 minutes, and it was the two substitutes who combined to open the scoring. Albrighton picked up the ball on the left wing before turning inside and crossing towards the centre of the area where Slimani lay in wait before the Algerian ousted Lamine Kone in the air to head home.
Sunderland got their big chance in the 77th minute when Jack Rodwell burst down the left hand side and pulled the ball back into the box where it fell to substitute Victor Anichebe, but the Nigerian could only strike the post before Defoe hit the side netting.
They were instantly punished for their failure to score and it was Albrighton at the heart of the move once again. The substitute beat Jones to the ball before driving down the left wing and pulling back towards Vardy, who took one touch before lashing high into the roof of the net to put the game beyond all doubt.
The win sees Leicester move up to 10th in the Premier League, while Sunderland remain rock bottom of the table and are now eight points from safety with eight games remaining.