Preston North End thumped Scunthorpe United 4-0 after two Joe Garner goals, a Chris Humphrey strike and a Miguel Angel Llera own goal saw the visitors run away the winners.
Oldham Athletic's summer signing Jonathan Forte continued his rich form in front of goal, scoring his third goal in two games. However, it wasn't enough as Leyton Orient responded with three goals to take all three points.
A Louis Thompson red card resulted in a second-half Izale McLeod penalty for Crawley which condemned Swindon Town to their first defeat of the season after beating Scunthorpe on the first day of the new campaign.
The only goalless draw of the day in League One went to Walsall and Bradford with both teams unable to find the back of the net.
Results in full: Bristol City 2-1 Colchester United, Chesterfield 2-1 Rochdale, Coventry City 1-0 Sheffield United, Crawley Town 1-0 Swindon Town, Crewe Alexandra 1-2 Barnsley, Doncaster Rovers 1-3 Port Vale, Gillingham 2-0 Yeovil Town, Notts County 0-1 Fleetwood Town, Oldham Athletic 1-3 Leyton Orient, Peterborough United 3-2 MK Dons, Scunthorpe United 0-4 Preston North End, Walsall 0-0 Bradford City