Johnstone's Paint Trophy holders Crewe Alexandra made it through to the second round after seeing off League Two side Accrington Stanley.
Chuks Aneke scored the only goal of the game 11 minutes from time to secure victory at the Alexandra Stadium.
Brentford claimed a thrilling 5-3 victory over AFC Wimbledon with Farid El Allagui grabbing a double for the home side.
Plymouth Argyle beat Cheltenham Town 5-4 in a penalty shootout following an exciting 3-3 draw.
Dagenham & Redbridge of League Two claimed a surprise 4-1 victory over League One Colchester United.
Wolves claimed a penalty shootout victory over Walsall after the two sides shared a 2-2 draw at Molineux.
Shaun Batt scored a hat-trick as League One leaders Leyton Orient claimed a 4-1 victory over Gillingham, while Oldham Athletic won at Shrewsbury Town by the same scoreline.
Hartlepool, who are yet to win a game this season in League Two, managed a shock 5-0 victory against League One side Bradford City.
Jamille Matt scored two second-half goals for Fleetwood Town as they came away from Tranmere Rovers with a 2-1 win.
Wycombe Wanderers beat their League Two counterparts Exeter City 2-0 thanks to goals from Matt McClure and Anthony Stewart, while Port Vale beat Bury 2-1 after two goals from Tom Pope.
Sheffield United and Portsmouth are through to the second round after winning penalty shootouts against Scunthorpe United and Torquay United.
A first-half goal from Callum McGregor was enough for Notts County to beat Burton Albion, while Milton Keynes Dons saw off 10-man Northampton Town 2-0 at the Stadium mk.
Results in full: Brentford 5-3 Wimbledon, Dagenham & Redbridge 4-1 Colchester, Gillingham 1-3 Leyton Orient, Hartlepool 5-0 Bradford, Tranmere 1-2 Fleetwood, Exeter 0-2 Wycombe, Port Vale 2-1 Bury, Crewe 1-0 Accrington, Shrewsbury 1-4 Oldham, Cheltenham 3-3 Plymouth (Plymouth win on penalties), MK Dons 2-0 Northampton, Notts County 1-0 Burton, Scunthorpe 0-0 Sheffield United (Sheffield United win on penalties), Torquay 0-0 Portsmouth (Portsmouth win on penalties), Wolves 2-2 Walsall (Wolves win on penalties).
