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 counter-attack throughout and it was he who grabbed the only goal of the game against the run of play after 25 minutes.
Third-placed Crystal Palace had the chance to cut the gap to two points as they hosted Huddersfield in the late game but in the end had to settle for a 1-1 draw.
Peterborough's flying start proved decisive as they edged Bolton 5-4 in a nine-goal thriller at London Road.
Buoyed by their surprise victory over leaders Cardiff last week, Posh raced into a two goal lead inside six minutes thanks to Lee Tomlin and Dwight Gayle.
Wanderers midfielder Keith Andrews reduced the arrears from the penalty spot but George Thorne's drive made it 3-1 shortly after half-time.
Another Andrews spot kick prompted Bolton's most promising period of the match but United defenders Mark Little and Gabriel Zakuani got in on the act to apparently make the points safe.
But there was a final twist as Wanderers substitutes Benik Afobe and Martin Petrov netted inside the final six minutes to set up a grandstand finish.
In-form striker Luciano Becchio continued his impressive goal scoring record against Middlesbrough to help Leeds kick off their new era with a 2-1 win.
The day after GFH Capital confirmed their 100 per cent buyout of the Whites, Becchio scored either side of the break to cancel out Lucas Jutkiewicz's opener and earn his side a fifth win in six npower Championship games.
Rhys McCabe struck his first senior goal and Jeremy Helan was also on target as Sheffield Wednesday climbed out of the bottom three of the Championship with a second successive win, 2-0 against Charlton.
Nikola Zigic's 89th-minute equaliser salvaged a point in a 2-2 draw for a youthful Birmingham against Burnley at St Andrew's.
Blues had gone behind in 15 of their previous 22 npower Championship matches before this match but it was they, fielding seven teenagers in their starting XI, who took the lead on the half-hour mark courtesy of Curtis Davies' header.
A contentious moment arrived just before the hour as Charlie Austin saw a goal chalked off when advantage could and should really have been played, but Burnley deservedly got their rewards soon after with two goals in three minutes.
Danny Ings levelled with a well-taken finish before almost straight from kick-off Ross Wallace, also with his first goal of the season, converted a stunning free-kick off the underside of the crossbar.
Marcus Tudgay's late goal condemned Millwall to a surprise defeat as Barnsley gave their Championship survival bid a welcome boost.
Tudgay struck in injury time after Chris Wood appeared to have salvaged a point for the Lions, who had lost just once in their previous 16 matches.
Ipswich came from behind to earn a point against fellow strugglers Bristol City at Portman Road, a 1-1 draw which keeps the Tractor Boys five points clear of their opponents.
Derek McInnes' visitors took an early lead through a fine strike from Neil Danns before Tommy Smith acrobatically drew the home side level.
Matej Vydra scored twice as Watford moved into the Championship play-off places with a 2-0 victory over Nottingham Forest.
The double took his tally for the season to 10, with the goals coming either side of Daniel Ayala being sent off for the visitors before the break.
More to follow
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