Walsall have moved to the top of the table following a comfortable win over Blackpool, which gives them a fourth straight win in the league.
Romaine Sawyers netted a brace to maintain the visitors' unbeaten start to the League One season, moving them two points clear at the top.
Walsall were able to move above Gillingham after they let in a late equaliser in their match against Peterborough United at London Road.
Adedeji Oshilaja appeared to have given the visitors the win with five minutes remaining, but Jon Taylor equalised for the Posh in stoppage time, leaving Gillingham fourth.
Barnsley looked like they were feeling the effects of extra time against Everton in the League Cup earlier this week as they slumped to defeat against Rochdale.
Calvin Andrew opened the scoring early on for the hosts, before Peter Vincenti and Ian Henderson also found the back of the net, giving Rochdale their first win in three outings.
Millwall slipped to their third defeat in four outings after Jay O'Shea netted a brace for Chesterfield, who move up to sixth with three wins from five games.
O'Shea gave the visitors an early lead at The Den, before putting the win beyond doubt with a late strike.
A last-gasp goal gave Bradford city their first win of the campaign in a closely-fought match with Port Vale.
It looked like the tie was going to finish level until Devante Cole scored the only goal of the game with just seconds remaining.
Colchester United recovered after conceding twice in the opening 20 minutes to claim a draw with Scunthorpe United, but Tony Humes's side are still without a win this season.
Paddy Madden and Kevin van Veen gave Scunthorpe a 2-0 advantage early on, but goals either side of half time from George Moncur and George Elokobi ensured that the home side picked up a point.
Sheffield United left it late in their match against Swindon Town, scoring twice in the space of five minutes to continue their strong start to the season.
Neill Collins opened the scoring from a corner inside the final 20 minutes, before Billy Sharp doubled the lead a couple of minutes later.
Wigan Athletic have jumped up to seventh after narrowly beating Crewe Alexandra at the DW Stadium, giving them their second win of the campaign.
Michael Jacobs netted the only goal of the tie, heading in inside the opening 15 minutes from a corner.
Doncaster Rovers netted twice in the opening half hour to set up their first win of the season, defeating Fleetwood Town.
Curtis Main and James Coppinger were both on target less than seven minutes apart, inflicting a second loss in four outings on Fleetwood.
Bury secured their fourth draw in five outings since winning promotion from League Two, coming from behind to draw with Oldham Athletic.
Tom Pope scored his second goal for his new club after Lee Croft had opened the scoring for the visitors midway through the first half.
Newly-promoted sides Shrewsbury Town and Burton Albion went head-to-head at the New Meadow, with a late goal from Mark Duffy clinching all three points for the visiting side.
The injury-time strike hands Burton their third straight win in the league, and a fourth in five outings.
Results in full (half-time scores in bracket): Blackpool 0-4 Walsall (0-1), Bradford City 1-0 Port Vale (0-0), Bury 1-1 Oldham Athletic (0-1), Colchester United 2-2 Scunthorpe United (1-2), Doncaster Rovers 2-0 Fleetwood Town (2-0), Millwall 0-2 Chesterfield (0-1), Peterborough United 1-1 Gillingham (0-0), Rochdale 3-0 Barnsley (2-0), Shrewsbury Town 0-1 Burton Albion (0-0), Swindon Town 0-2 Sheffield United (0-0), Wigan Athletic 1-0 Crewe Alexandra (1-0)
