Jesse Marsch's first game as Leeds boss ended in defeat as Harvey Barnes scored the only goal to give Leicester their second Premier League win of the week.
The winger produced Leicester's one moment of attacking quality with a precise angled finish midway through the second half of a game in which they had been largely second best.
It has been an emotional week for Leeds since the departure of Marsch's much-loved predecessor Marcelo Bielsa following a chastening month in which they conceded 20 goals and picked up only one point from a possible 15.
But they produced a lively and energetic display at the King Power Stadium that showcased a change of shape and the hard-pressing, direct football preferred by their American manager.
Better finishing from Jack Harrison, Rodrigo, Junior Firpo or Raphinha would have given Leeds a win they so desperately need to ease their relegation concerns.
Having spurned them, they left themselves vulnerable to a decisive moment like the one Barnes produced.
Victory lifted Leicester to 10th in the table. Leeds remain two points above the bottom three, having played two games more than 18th-placed Burnley.
Whether you have Bielsa, Marsch or any other manager in charge, the old adage remains true: if you don't take your chances when on top, you risk being punished.
It was a recurring failing of Leeds under Bielsa that they failed to make good on the bountiful chances they often produced in games long before they were shipping goals to the tune of 20 in a month.
While Marsch changed a number of things in his first game in charge - a new 4-2-2-2 formation and quicker play through the middle - it was the old problem of conversion that cost Leeds.
Kasper Schmeichel can take some credit for repelling the visitors, producing saves to deny Dan James, Harrison, Rodrigo and, in the best of all from close range, Raphinha.
Caglar Soyuncu was also on hand to brilliantly block Junior's goalbound shot from inside the box.
This all set up Leicester, who until then had offered very little barring the occasional threat of the returning Jamie Vardy getting in on goal with long balls over the top.
Barnes is a player building his reputation weekly and, after sharing a one-two with Kelechi Iheanacho, he slotted a low shot across goal and past the diving Illan Meslier.
Leeds continued to press forward, but their moment had passed and Leicester were able to see the game out to add another three points to those earned at Burnley on Tuesday.
Marsch gathered his players in a huddle in the centre circle at full-time. His message will surely have been to focus on the multiple positives.
No points, but plenty to take forward into a run of crucial games beginning with Aston Villa and Norwich at home next week.