Leicester City inched ever closer to the Premier League title with a gritty success at the Stadium of Light.
There wasn’t much to choose between the sides throughout but Leicester’s England internationals made the difference.
Danny Drinkwater set up Jamie Vardy for the crucial breakthrough goal midway through the second half and the striker added a second deep into stoppage time.
The win moves Leicester ten points clear of second-placed Tottenham ahead of their game against Manchester United at White Hart Lane.
For Sunderland and boss Sam Allardyce, there is now the promise of a make-or-break clash with Norwich at Carrow Road next weekend.
The first half on Wearside was one of few chances.
Wes Morgan had an opportunity to make it two goals in a week for Leicester but the big defender got his timing all wrong as he glanced a header wide on 15 minutes.
At the other end Patrick van Aanholt’s teasing cross just failed to pick out the in-rushing Wahbi Khazri.
Leicester felt they should have had a penalty on 26 minutes, Shinji Okazaki going down under a challenge from DeAndre Yedlin but Anthony Taylor waved play on.
In first-half stoppage time, Kasper Schmeichel had to be alert to deal with a shot from Fabio Borini after some good work from the lively Jermain Defoe on the Sunderland right.
Both teams had some early sights of goal in the second half.
Borini and Defoe enjoyed snapshots for Sunderland while Okazaki blasted over the crossbar at the other end.
On 66 minutes, Leicester made the crucial incision.
Drinkwater broke out of defence and launched a terrific long-range pass for Vardy to run onto and, having got behind Younes Kaboul, he arrowed a shot beyond Vito Mannone into the corner of the net on his right foot.
Sunderland’s best chance of a leveller arrived nine minutes from full time.
Van Aanholt’s shot from the edge of the box was deflected into the path of sub Jack Rodwell but from six yards out and with the goal at his mercy, he blazed over the bar.
Vardy made the most of a high clearance in the fifth-minute of stoppage time, skipping away from the Sunderland cover and beating Mannone to the ball before finishing into an empty net to leave Leicester standing on the brink of title glory.