Dexter Blackstock's second-half strike secured Nottingham Forest a narrow victory at League Two Fleetwood.
The striker saw his header from Andy Reid's left-wing cross saved by Scott Davies but bundled in the rebound.
Blackstock also hit the crossbar with a point-blank effort, while Greg Halford saw his overhead kick saved.
Fleetwood, playing in their first League Cup tie, went close in the first half through Jon Parkin, while Steven Gillespie fired over after the break.
Forest substitute Marcus Tudgay came close to getting Forest's second, but put his header wide moments after replacing Blackstock.
Parkin also had a chance to level in injury time but saw his looping header saved by Karl Darlow, who made his first competitive start for Forest.
VIEW FROM THE DRESSING ROOM
Fleetwood Town manager Micky Mellon told BBC Radio Lancashire:
"The biggest tribute I can pay to my players is that anyone coming here not knowing the two teams, you wouldn't have said there was two levels between them.
"Sometimes we probably shaded it, without creating loads and loads of chances.
"We'll take the lessons from this game and we'll make sure it makes us a better team.
"We'll take a lot of pride in knowing that, for large periods, we matched Nottingham Forest."
Nottingham Forest manager Sean O'Driscoll told BBC Radio Nottingham:
"I was pleased with our organisation. We have thrown a back four together and that was their first 90 minutes.
"We managed to change things at half-time without changing personnel. The versatility of Greg Halford has helped us and then will stand us in good stead.
"I think the result goes to us but the plaudits go to Fleetwood. I thought they were excellent. They will do well in League Two."
Fleetwood Town 01 Davies 02 Beeley 03 Howell 05 McNulty 15 McLaughlin (Fowler - 69' ) 28 Mawene 11 Nicholson 18 McGuire Booked 09 Parkin 14 Mangan 26 Ball (Gillespie - 63' ) Substitutes 40 Thewlis 12 Brown 13 Goodall 08 Milligan 10 Fowler 31 Kinsella 19 Gillespie Nottingham Forest 12 Darlow 03 Harding 05 Collins 15 Halford 18 Moloney 26 Ayala 07 Guedioura 10 McGugan 11 Reid 28 Majewski (Greening - 88' ) 23 Blackstock (Tudgay - 81' ) Substitutes 31 Evtimov 16 Lascelles 14 Greening 17 McGoldrick 20 Tudgay 25 Miller 27 Derbyshire