First-team duo Ahmed Musa and Eldin Jakupovic featured for Leicester, with Musa setting up a chance for Kiernan Dewsbury-Hall and then winning a corner from which Josh Knight headed just wide.
At the other end Jakupovic denied Jack Diamond's effort.
The Foxes are now a point behind second-placed Everton, while Sunderland moved above Tottenham Hotspur into 10th.
Leicester: 24 Nov v Derby County (A) PL2
Sunderland: 26 Nov v Swansea City (H) PL2