Cardiff bounced back from their surprise home defeat to Peterborough with a smash-and-grab victory at Leicester to move three points clear at the top of the Championship.
Leicester laid siege to the Bluebirds' goal in the first half, with chance after chance going begging. David Marshall made a handful of saves to keep the Foxes at bay, and when he was beaten by Andy King's long-range effort, a post came to his rescue.
Craig Bellamy looked a threat on the counterattack throughout and it was he who grabbed the only goal of the game against the run of play after 25 minutes.
The Wales international showed great technique after collecting Craig Conway's pass to find the bottom left-hand corner of the net from 12 yards out.
The Cardiff manager, Malky McKay, was full of praise for the Welsh striker. "He never gave the defenders a minute's peace. He is comfortable being with this group of
players and enjoying his football."
The Foxes were unchanged from the side that started last weekend's defeat at Millwall, although striker Martyn Waghorn was fit enough for a place on the bench following surgery to remove his appendix.
Mackay made three changes after seeing his side's 100 per cent home record ended by struggling Peterborough.
Leicester started brightly, Danny Drinkwater firing over early on. David Nugent became the first home player of the afternoon to be frustrated by Marshall when the Scot parried his effort from the edge of the area. King struck a post after 13 minutes when the ball broke to him outside the area after Marshall had kept out Wes Morgan's header.
Marshall then twice denied Anthony Knockaert when the Frenchman let fly from long range before Bellamy delivered the killer blow from the visitors.
Jamie Vardy might have done better than head over the crossbar before half-time in what turned out to be Leicester's final realistic chance.
Back-to-back defeats are a blow to Leicester's automatic promotion aspirations, which will come under intense scrutiny again on Boxing Day when they travel to their manager Nigel Pearson's former club Hull. A frustrated Pearson said afterwards: "When you create as many goalscoring opportunities as we did you would expect to score.
"But today we came up against a side that, to be fair to them, defended well and had a lot of experience."
McKay was delighted with the way his players reacted to their defeat last week. "This was a really big win for us after losing to Peterborough and it was smashing the way we bounced back from that. I'm delighted," he said.
"We knew we were coming to play a very good team and that it was going to be tough. But I think this was a great advert for the Championship. It was two teams playing attractive football and at a hell of a tempo."
Leicester (4-4-2): Schmeichel; Konchesky, Morgan, Whitbread, De Laet; Dyer (Lingard, 68), King, Drinkwater, Knockaert (Marshall, 68); Nugent, Vardy (Waghorn, 51).
Cardiff (4-4-2): Marshall; Taylor, Hudson, Turner, Connolly; Kim (Cowie, 55), Whittingham, Mutch (Gunnarsson, 76), Conway; Bellamy, Helguson (Gestede, 51).
Referee Graham Salisbury.