Wolves and Birmingham City boosted their prospects of automatic promotion from the Championship as Reading were held at Plymouth Argyle.
Cardiff City enjoyed an emphatic home win, Sheffield United stretched their unbeaten run away from home, but Preston North End's promotion hopes were dented.
Derby County, Watford and Blackpool all picked up important wins at the bottom end of the table as Nottingham Forest drew with Swansea City.
Sylvan Ebanks-Blake's 23rd goal of the campaign after just five minutes at Hillsborough earned Wolves a second 1-0 away win of the week against Sheffield Wednesday.
January signing Keith Fahey struck on the stroke of half-time as Birmingham battled to a 1-0 triumph at home to Southampton, who had won their previous three games.
Reading lost ground on the leading two after twice being forced to come from behind to claim a 2-2 draw at improving Plymouth Argyle.
United States international Eddie Johnson grabbed his first goal in English football as the on-loan striker put the seal on Cardiff City's convincing 3-0 victory at home to Doncaster Rovers.
Crystal Palace ended a run of four games without a goal as Anthony Stokes and Neil Danns helped Neil Warnock's men come from behind to beat promotion-chasing Preston 2-1 at Selhurst Park.
Queens Park Rangers have now gone seven games without a win after being held to a 0-0 draw at home by Sheffield United, who have not lost for 13 matches away from home in the Championship.
Jason Scotland's 20th goal of the season was only enough to earn Swansea City a point as Lewis McGugan salvaged a 1-1 draw for Nottingham Forest at the City Ground.
Charlton Athletic's bid for survival took another knock as Tamas Priskin's 83rd minute winner boosted Watford's hopes of staying in the division after a 3-2 success at the Valley.
Rob Hulse pounced for a late winner as Derby County put a dent in Bristol City's promotion hopes with a 2-1 win at Pride Park.
Brett Ormerod's first goal since returning to Bloomfield Road set Blackpool on their way to a priceless 2-0 home win over relegation rivals Norwich City.