Steve Bruce’s side, who are second in the Championship table and eight points behind leaders Cardiff, beat Charlton thanks to striker Gedo’s 33rd-minute effort.
The Tigers remain three points ahead of third-placed Watford, who thrashed Birmingham 4-0 at St Andrew’s.
Gianfranco Zola’s side crushed the beleaguered Blues thanks to a brace from Troy Deeney and goals from Ikechi Anya and Almen Abdi.
Crystal Palace were also victorious in their chase for promotion as Ian Holloway’s men beat Middlesbrough 4-1 at Selhurst Park.
Striker Glenn Murray netted a brace, while Peter Ramage and substitute Kevin Phillips were also on target.
Derby were held to a goalless draw at home to Wolves as they failed to put further pressure on the play-off places, while new Nottingham Forest boss Billy Davies saw his side draw 1-1 with Bolton at home after Craig Davies cancelled out Andy Reid’s opener.
Mick McCarthy’s Ipswich moved further away from relegation trouble with a 1-0 win over Blackpool at Portman Road, with substitute Michael Chopra securing the game’s only goal.