Cardiff swept to the top of the Championship with a 4-0 demolition of Burnley on Saturday while previous leaders Leicester slumped to a 2-1 defeat against managerless Crystal Palace.
Malky Mackay's team started the day level on points with Leicester and finished it three clear at the top thanks to a ruthless display at the Cardiff City Stadium in south Wales.
The Bluebirds got off to a flying start with midfielder Joe Mason netting after three minutes and Craig Noone added the second goal four minutes before half-time.
Matthew Connolly put the result beyond doubt with his 82nd minute strike and Aron Gunnarsson wrapped up the victory with the fourth goal three minutes later.
Cardiff's dominant display was perfectly timed as Nigel Pearson's Leicester slipped up at home to Palace.
The fourth placed Eagles, without a manager after Dougie Freedman's move to Bolton, took the lead when Damien Delaney struck in the 23rd minute and Peter Ramage increased the south Londoners' advantage five minutes later.
Andy King's last-minute effort was no consolation for Leicester, who drop to second place.
Middlesbrough, in third place, moved level on points with Leicester after coming from behind to beat Bolton 2-1 at the Riverside Stadium.
South Korea midfielder Lee Chung-yong put Bolton ahead in the 42nd minute, but a brace from Australian striker Scott McDonald, in the 67th and 85th minutes, sealed the points for Middlesbrough.
Blackburn, still looking for a permanent manager after Steve Kean's departure, remain firmly in the promotion hunt after a stoppage-time goal from Scotland striker Jordan Rhodes earned a 1-0 win against Watford at Ewood Park.
Nottingham Forest moved into the play-off places thanks to a 4-1 win at Barnsley, while Wolves slipped out of the top six after being held to a 1-1 draw by Charlton at Molineux.
At the other end of the table, Sheffield Wednesday won for the first time in 11 matches as Dave Jones' team thrashed bottom of the table managerless Ipswich 3-0 at Portman Road.
Ross Barkley scored early in each half, with Michail Antonio adding a third late on for the Owls, who remain in the bottom three.
New Zealand striker Chris Wood scored twice as Millwall boosted their survival bid with a 4-0 rout of Huddersfield at The Den.
James Henry added a third 11 minutes from time and Liam Trotter got the fourth after Huddersfield had Jack Hunt sent off.
Peterborough cruised to a 3-0 win over Derby at London Road, Blackpool drew 1-1 at home to Brighton, while Leroy Lita's goal earned Birmingham a 1-0 victory at Leeds.