Leicester City had an uncomfortable weekend off as all their big rivals for the top-two spots won.
Cardiff, Hull, Watford and Crystal Palace all won to see City drop to fifth – admittedly with games in hand.
Cardiff stretched their unbeaten league run to nine matches with a 2-1 win over Bristol City strengthening their position at the top.
Home debutant Fraizer Campbell scored both goals for the Bluebirds, opening the scoring moments before the half-time whistle before finding the target again after 58 minutes from close range.
A stoppage-time own goal from Ben Nugent denied Cardiff a clean sheet but they remain eight points clear of nearest challengers Hull, who were 1-0 winners at home to Charlton.
Mohamed Gedo made the most of an error from goalkeeper Ben Hamer to stab home the only goal after 33 minutes at the KC Stadium.
Watford kept up the pressure on the top two with a 4-0 hammering of Birmingham.
Troy Deeney scored twice for the Hornets, after 38 and 62 minutes, with Ikechi Anya (43) and Almen Adbi (89) also on target in a one-sided affair.
Watford are three points behind the Tigers and one ahead of Crystal Palace, who climbed to fourth with an easy 4-1 success over fellow play-off hopefuls Middlesbrough.
Glenn Murray fired Palace in front after nine minutes before second-half goals from Peter Ramage and Murray again put the hosts into a commanding lead.
Faris Haroun replied for Boro 10 minutes from time but Kevin Phillips added more misery four minutes later.
Wolves sit just a point above the relegation zone after playing out a goalless draw with Derby.
Paul Ince is set to be unveiled as Blackpool manager later today after he watched the Tangerines slip to a 1-0 defeat at Ipswich on Saturday.
The former England international sat in the directors' box at Portman Road as Michael Chopra's 50th-minute strike settled the contest.
While Blackpool are yet to confirm Ince's arrival, caretaker boss Steve Thompson revealed after the game that the 45-year-old was on the brink of a deal.
Leicester City travel to Blackpool on Saturday for what will effectively be Ince's first game in charge of his new side.
All the results: Birmingham 0 Watford 4, C Palace 4 Middlesbro 1, Derby 0 Wolves 0, Hull 1 Charlton 0, Ipswich 1 Blackpool 0, Nottm Forest 1 Bolton 1, Cardiff 2 Bristol City 0
