Leeds United’s 5-4 penalty shootout success at Fleetwood has earned them a trip to league Two Luton Town, who had a shock 3-1 home win over Aston Villa.
Premier League newcomers Hull City and Middlesbrough enter the competition at Exeter City and Fulham, respectively.
Leeds head coach Garry Monk never doubted his young Leeds team would overcome the challenge of Fleetwood, though they were forced to go the distance after Marcus Antonsson booked extra-time with a late goal at Highbury Stadium.
Aaron Holloway had opened the scoring for the Cod Army, with Ashley Hunter and Chris Wood exchanging goals to make it 2-2 after 30 additional minutes.
Ultimately, Eggert Jonsson had his spot-kick saved by Robert Green after Pablo Hernandez put his away, much to the delight of Monk.
He said: “I thought it was a proper cup tie and I thought it was a credit to both teams.
“It was a battle for both teams in tough conditions. We gave ourselves an uphill fight but those young players showed great courage.
“Credit to Fleetwood, they defended very well.
“But we kept going, kept believing in what we were doing and when we got the equaliser that was proven. From then we looked like going on to win.”
Uwe Rosler, who was previously in charge at Elland Road for five months, praised his plucky Fleetwood side.
He said: “My players were fantastic, our penalties were very good.
“This Leeds team is not comparable with the one I had a year ago. You now have a Championship team with Premier League qualities.
“The Premier League quality won that game, that was the difference.
“We gave them problems, our three central strikers did well.”
Aston Villa’s Roberto Di Matteo has called for his side to go back to basics after crashing out of the EFL Cup at Luton.
The Villa chief, who has now lost his first two competitive games since taking charge of the club, saw the hangover from relegation out of the Premier League continue as they were deservedly knocked out by the Hatters.
Championship side Villa dominated the opening 20 minutes, hitting the frame of the goal twice and taking the lead through Jordan Ayew’s 13th-minute strike.
But Luton levelled nine minutes before the break through Jake Gray before Cameron McGeehan put Luton ahead early in the second half and Jores Okore comically put through his own net in the 66th minute.
Di Matteo said: “We went deservedly ahead, and then let Luton back into the game as second half they dominated us and we looked disjointed as a team.
“It wasn’t a team performance, also difficult to explain from first half to second half how we changed so much.”
Villa are without a win in any competition since February 6 and Di Matteo admitted the team need to toughen up mentally.
The former Chelsea manager added: “Certainly there’s some fragility there, because after we conceded the equaliser you could see they were a little bit nervous, but I didn’t expect in the second half we would play like that.
“We have to work together as a team and try to get a win and grow their confidence.
“We let ourselves down and lose games, so we probably have to go back to basics, defend well, defend our box and take our chances. We did create chances but we need to make sure we don’t concede so easily.”
Luton manager Nathan Jones said: “I’m very, very proud, I thought they were excellent.
“We started very slowly but once we realised we could affect a football game against Aston Villa, I thought we were excellent, especially second half.
“They showed they could competed first half but second half they showed a real desire to win a football match and I thought we were excellent.
“We had a little bit of fortune at times, they hit the woodwork, but it was slim margins.”
League Cup 2nd round draw:
QPR v Rochdale
Scunthorpe v Cardiff/Bristol City
Watford v Gillingham
Peterborough v Swansea
Everton v Yeovil
Millwall v Nottm Forest
Sunderland v Shrewsbury
Luton v Leeds
Chelsea v Bristol Rovers/Bristol City
Burton v Liverpool
Blackburn v Crewe
Accrington v Burnley
Crystal Palace v Blackpool
Morecambe v Bournemouth
Preston v Oldham
Oxford v Brighton
Reading v MK Dons
Fulham v Middlesbrough
Newcastle v Cheltenham
Exeter v Hull
Derby v Carlisle
Northampton v West Brom
Wolves v Cambridge
Stevenage v Stoke
Norwich v Coventry
Ties to be played week commencing August 22.