Wigan Athletic have progressed to the third round of the Johnstone's Paint Trophy after coming from behind twice to seal a 3-2 win at Crewe Alexandra.
Marcus Haber put the hosts into the lead just six minutes into the game with a close-range strike, but Jordi Hiwula equalised four minutes later with an acrobatic effort.
Crewe ended the first half in front after Ryan Colclough slotted the ball into the bottom-left corner in the 35th minute, but two goals in six second-half minutes from Hiwula and Yannick Wildschut saw Gary Caldwell's side through.
Millwall also advanced to the next stage of the competition after second-half goals from Aiden O'Brien and Steve Morison proved enough to see off Northampton Town.
Blackpool, who fell from the Championship last season alongside the Latics and the Lions, completed a hat-trick of victories for the relegated sides with a 2-1 win at Port Vale.
Sheffield United cruised into the third round of the tournament following an emphatic 5-1 win over a hapless Notts County side, who conceded three penalties and saw Haydn Hollis sent off at Bramall Lane.
Yeovil Town, who suffered back-to-back relegations from the Championship into League Two, came out on top against Coventry City on penalties following a goalless draw in normal time.
Bristol Rovers struck twice in the first 11 minutes of their game against Wycombe to claim a 2-0 win at the Memorial Stadium, while Oxford United, Plymouth Argyle and York City won by the same scoreline in their respective games against Swindon Town, Exeter City and Doncaster Rovers.
In other results, Crawley Town fell to a heavy 3-0 defeat against visiting Southend United, Fleetwood Town edged past Shrewsbury Town 2-1, and Gillingham beat Luton Town by the same scoreline, as did Rochdale against Chesterfield.
The match between Bradford City and Barnsley, meanwhile, was called off five minutes before kickoff due to heavy rain.
Results in full: Crewe Alexandra 2-3 Wigan, Bradford P-P Barnsley, Bristol Rovers 2-0 Wycombe, Bury 0-1 Morecambe, Crawley 0-3 Southend, Fleetwood Town 2-1 Shrewsbury, Gillingham 2-1 Luton, Millwall 2-0 Northampton, Oxford Utd 2-0 Swindon, Plymouth 2-0 Exeter, Port Vale 1-2 Blackpool, Sheff Utd 5-1 Notts County, Yeovil 0-0 Coventry (Yeovil win 4-3 on penalties), York City 2-0 Doncaster
