Rio Ferdinand endured a torrid start to his Leeds' career as Leicester's first half show sunk the Yorkshire club at Filbert Street.
Goals from Robbie Savage, Ade Akinbiyi and Gerry Taggart in the first half hour stunned David O'Leary's side.
The visitors were seldom in the contest until the final quarter of an hour, when Mark Viduka scored a consolation.
The visitors adopted a three at the back formation to accomodate the talents of Ferdinand.
But despite his presence and that of fellow big men Radebe, Jonathon Woodgate and Dominic Matteo, all three goals came from headers.
Such was the confusion in the Leeds defence that Woodgate was substituted before half time as O'Leary returned to a 4-4-2 formation.
Savage's instinctive header
The result will almost certainly raise questions about Ferdinand's position in the side, for he can scarcely have looked more out of place.
The game had hardly caught fire when Savage opened the scoring in the eighth minute.
Darren Eadie's swerving shot seemed to deceive Paul Robinson, who could only palm the ball into the direction of Savage.
The Welshman's headed contact with the ball was either instinctive or very lucky.
The first attempt from a Leeds player came from Viduka, curling a weak right-footed shot wide.
Ferdinand's first contribution was from a Leeds free-kick but the country's most expensive player spooned a shot over the crossbar.
The runs of Savage and Muzzy Izzet caused the new look Leeds plenty of problems.
After a couple of minutes of pressure, Frank Sinclair's floated cross from the right found a posse of Leicester players waiting.
Akinbiyi rose highest to nod the ball down past Robinson for a two-goal lead after just 17 minutes.
Leeds' frustration was underlined by Alan Smith's late challenge on Callum Davidson in the 25th minute.
It earned the diminutive striker the first caution of the afternoon and captain Lucas Radebe followed him into the book for a challenge on Eadie.
It was Davidson who played the creative role for the third goal.
He floated in a free-kick from 30 yards which Taggart had no problem heading past Robinson.
The third goal finally drew some life from the visitors.
But a goalmouth scramble came to nothing and Lee Bowyer's strong run and shot forced the first save from Simon Royce.
Leeds' change in formation was no surprise, with Woodgate replaced by Jason Wilcox.
The second half saw the visitors dominate possession and territory.
Possibly the best moment of the game for them came when Australian winger Harry Kewell came off the bench after lengthy injury absence.
Leeds fightback
The game should already have been stopped when Radebe's miserable afternoon came to an end.
A nasty tackle by Taggart started the Leicester attack but it was ignored.
Seconds later Radebe received his second yellow card for tripping Izzet.
Leeds were forced to reshuffle again with Matteo moving into the centre of defence and they showed plenty of late fighting spirit.
Fifteen minutes from the end Viduka smashed the ball into an empty net after Royce had failed to hold onto Smith's close range effort.
Dacourt hit the post from a free kick and Kewell missed a golden chance from ten yards but Leicester held on to their comfortable lead.
Leicester City: Royce, Rowett, Davidson, Sinclair, Elliott, Taggart, Lennon, R. Savage, Izzet, Akinbiyi, Eadie. Subs: Price, Impey, Oakes, Guppy, Gunnlaugsson.
Leeds United: Robinson, Kelly, Dacourt, Radebe, Woodgate, Viduka, Bowyer, Smith, Jones, Matteo, Ferdinand. Subs: Kewell, Mills, Wilcox, Harte, Milosevic.
Referee: S Bennett (Orpington)