The Cottagers claimed a 1-0 win over Reading to secure their fourth straight league victory, as well as extending their unbeaten run to 20 games.
Neil Warnock's charges, who had been on a lengthy unbeaten run prior to losing against Wolverhampton Wanderers on Friday, have now lost two games in a row and drop to third in the table.
In-form Millwall have surged into the Championship playoff spots thanks to a 2-0 win at Bolton Wanderers, with Tom Elliott and Ben Marshall grabbing the goals for last season's League One playoff winners.
Birmingham City's relegation battle has suffered a blow in the form of a 3-1 defeat at Bristol City, but the Blues remain three points clear of the bottom three as the teams below them all dropped points.
Alongside Bolton's loss to Millwall, Burton Albion were hammered 5-0 at home to Hull City, Barnsley suffered a 1-0 defeat at Ipswich Town, and Sunderland drew 1-1 with Norwich City.
Elsewhere, Brentford ran out 1-0 winners at Nottingham Forest, Preston North End beat out-of-form Leeds United 3-1, Queens Park Rangers claimed a 4-2 win over Sheffield Wednesday, and Sheffield United won 2-1 against Middlesbrough.
Results in full: Aston Villa 1-0 Cardiff City, Bristol City 3-1 Birmingham City, Burton Albion 0-5 Hull City, Fulham 1-0 Reading, Ipswich Town 1-0 Barnsley, Nottingham Forest 0-1 Brentford, Preston North End 3-1 Leeds United, Queens Park Rangers 4-2 Sheffield Wednesday, Sheffield United 2-1 Middlesbrough, Sunderland 1-1 Norwich City