Wolves remain top of the Coca-Cola Championship after claiming a 2-1 home win over Crystal Palace.
Sylvain Ebanks-Blake and Andy Keogh scored for Mick McCarthy's men, who remain unbeaten.
Birmingham remain unbeaten too and are joint top with Wolves after winning 2-1 at Bristol City through Cameron Jerome and a Louis Carey own goal.
Preston are still third following a 2-1 home win over Nottingham Forest while Reading went fourth after thumping Sheffield Wednesday 6-0 with Kevin Doyle hitting his second hat-trick in three games.
Peter Whittingham gave Cardiff a 1-0 win at Barnsley to send the Bluebirds into the top six, and Andy Gray's early strike was enough for Charlton to get back to winning ways with a 1-0 success at Doncaster.
Plymouth celebrated their first victory of the season after winning 2-1 at Watford, and Burnley followed up their first win on Saturday by triumphing 2-0 at home to Lancashire rivals Blackpool.
A late Ashley Williams equaliser denied Derby three points at Swansea, with Sheffield United and Coventry also drawing 1-1 at Bramall Lane.