Leicester suffered their seventh successive Premier League defeat in a 2-0 win for Fulham at the King Power Stadium.
Emile Smith Rowe and Adama Traore struck in the second half for the Cottagers, who won their first game since Boxing Day to lift them back into the top half.
The Foxes, who remain 19th in the table, have lost seven of their nine Premier League games under Ruud van Nistelrooy, who was the subject of criticism from some sections of Foxes supporters.
After the hosts missed a number of chances in the first half, Smith Rowe punished them with an early goal after the break with a brave diving header.
Harry Wilson’s cross was helped on by Sasa Lukic and the former Arsenal star threw himself in front of Jakub Stolarczyk to net his fourth of the season.
Traore secured the points for Marco Silva’s men in the 68th minute with a well-struck side-footed volley which flew past Stolarczyk into the bottom corner.
West Ham vs Crystal Palace
Jean-Philippe Mateta scored twice as Crystal Palace inflicted a second defeat in three games for Graham Potter as West Ham boss.
After a goalless first half, Mateta latched onto a brilliant Eberechi Eze through ball to stroke the ball past Lukas Fabianski shortly after the break.
Then with two minutes remaining, Mateta played a pass into the path of Eddie Nketiah, who was wiped out by the West Ham keeper as the Eagles were awarded a penalty.
The French striker stepped up to take the spot-kick which squirmed past Fabianski to seal the three points.
