Robbie Willmott and Padraig Amond were the heroes as League Two minnows Newport – the lowest-ranked side in the last 16 – bridged a gap of 57 places between themselves and Championship side Middlesbrough on the league ladder.
It was a thoroughly miserable evening for Boro managerTony Pulis, who was brought up just a few miles away from Rodney Parade.
But he can have no complaints as his side were second best in every department in joining a recent list of Rodney Parade cup casualties that also includes Leeds United and Leicester City.
Manchester City will provide far sterner opponents on February 16, but even the Premier League champions will not welcome the tight confines of this ground and the fervent atmosphere that comes with it.
Newport’s passage to the fifth round for only the second time –the previous occasion was in the 1948-49 season – was confirmed by two second-half goals.
Winger Willmott, having run Boro ragged in wide areas in the first half, opened the scoring two minutes after the break when he advanced 30 yards unchecked through the middle before dispatching a fine finish.
The scorer turned provider midway through the half with a superb move straight off the training ground.
Amond darted away from his marker to reach Willmott’s corner at the near post and the clever movement was matched with a ferocious finish inside Dimi Konstantopoulos’s near post.
Heavy rain had made conditions difficult, but the two sides soon settled down to producing an absorbing tie, played at a frenetic pace.
Jonny Howson fizzed the first opening wide, but Boro were fortunate to survive a strong penalty appeal for handball and a goalmouth scramble in the space of a minute.
Konstantopoulos was grateful to drop on the ball on his goalline after Jamille Matt and Amond both stabbed goalwards without conviction. The Greek goalkeeper had to be alert again to stop an Amond header looping in at the far post.
But Boro were almost ahead when Jordan Hugill raced on to Howson’s pass and struck the outside of a post from 20 yards.
But it was Newport who carried the greater threat and, after Konstantopoulos’s face came to the rescue by denying Amond from close range, Joss Labadie just failed to connect with Regan Poole’s cross.
Willmott was a constant danger down the right and another fine run and cross from the winger ended with Konstantopoulos pushing out Amond’s point-blank header.
Matt sent another header on to the roof of the net and Boro were relieved to get to the interval still level. But parity did not last for long as Willmott, collecting the ball just inside home territory, advanced to the edge of the area and unleashed a 20-yard drive past Konstantopoulos’s despairing dive.
Pulis turned to his bench quickly to make three substitutions, but Boro huffed and puffed after Newport sealed matters with Amond, who had scored the winner in the previous round against Leicester, showing his goal knack again.
Exiles boss Michael Flynn thinks Newport will make £1m from this cup run, with more TV money against City to come.
But, for now, it is all about the glory and Newport fans were celebrating one of the club’s most memorable nights wildly at the final whistle.
Newport County: Day, Poole, O’Brien, Demetriou, Willmott (Pipe 86), Bennett, Bakinson, Labadie (Dolan 74), Butler, Amond, Matt. Unused substitutes: Marsh-Brown, Sheehan, Hornby-Forbes, Crofts, Townsend.
Middlesbrough: Konstantopoulos, Ayala, Flint, Fry, McNair (van La Parra 46), Howson, Clayton, Wing, Friend, Hugill (Gestede 57), Assombalonga (Fletcher 61). Unused substitutes: Downing, Tavernier, Lonergan, Besic.
Referee: Stuart Attwell (Warwickshire).