Padraig Amond led the charge at Cambridge United and Newport County manager Michael Flynn said: “It was an absolutely outstanding performance.”
The Exiles won 4-1 in the Carabao Cup tie and earned their place in Thursday’s second round alongside Premier League clubs.
County will be in the South section – and could draw Welsh rivals Cardiff City.
Bournemouth, Brighton and Southampton are among other possibilities.
Amond scored two goals in four minutes during the first half and almost added a third, while Jamille Matt made it 3-0 just after half-time.
Substitute Antoine Semenyo made it 4-0 before the U’s netted a consolation through Ade Azeez.
“An absolutely outstanding performance,” said Flynn. “We were professional, clinical and ruthless. That’s what I have been asking for.
“We have set standards and need to keep to these standards.
“The finishing was first class. Our second goal was the best we have scored since I have been manager, an unbelievable goal.”
Flynn was talking about Amond’s second strike. There were nine Newport players involved in a flowing move and 14 passes before the Irish hit-man produced a clinical finish.
Now Flynn and his County team turn to their League Two clash against Exeter City away this Saturday.
Newport headed home to South Wales overjoyed with a second successive victory following their 1-0 triumph against Crewe on Saturday.
U’s manager Joe Dunne said: “It’s my responsibility, I take full responsibility for the defeat. It’s a bad night, everything was poor.
“No argument, we were comprehensively beaten. Defensively we were really poor as a whole team.”
Mike Flynn made four changes to the starting line-up for the win against Crewe. Goalkeeper Nick Townsend and Tyreeq Bakinson were both called in to make their debut.
Newport set up 3-4-1-2 with Scot Bennett, Mickey Demetriou and Fraser Franks combining at the heart of defence, while Tyler Forbes returned and joined Dan Butler in the wing-back positions.
Bakinson took up a holding midfield role alongside Matty Dolan, just behind Josh Sheehan with Matt and Amond in attack.
Cambridge had beaten promotion favourites Notts County 3-2 in their last match, but they were second best against Newport at Abbey Stadium.
Newport County AFC (3-4-1-2): Day, Forbes, Franks, Bennett, Demetriou (capt), Butler, Dolan (Cooper 79), Bakinson, Sheehan (Marsh-Brown 68), Amond, Matt (Semenyo 68). Subs not used: Day, Harris, Foulston, Collins.
Cambridge United (4-3-3): Mitov, Halliday, Darling, Taft, Carroll, O’Neil, Deegan (Corr 58), Maris, Osadebe (Knowles 85), Azeez, Lambe (Amoo 58). Subs not used: Pilkington, Davies, John, Squire.
Referee: Andy Davies.
Attendance: 1,618 (101 away).
