Newport thwarted Cheltenham’s bid to clinch the League Two title with a week to spare and improved their chances of reaching the play-offs with a 1-0 win at Rodney Parade.
Michael Duff’s Robins had clinched promotion with their 1-1 draw with Carlisle in midweek and hoped to claim their first Football League crown with victory in Wales.
But Joss Labadie’s fourth-minute goal delayed any further celebrations and left them two points ahead of second-placed Cambridge heading into the final week.
Newport’s win would have been enough to clinch a play-off spot if not for Exeter scoring in the sixth minute of added time to beat Bolton, meaning County now need a point from their final game at relegated Southend to secure a top-seven finish.
County skipper Labadie hammered home from 25 yards to open the scoring.
The visitors were all at sea and it took some harsh words from captain Ben Tozer, against his old club, to spark them into life.
It was from a long throw by Tozer that Cheltenham created their first chance a few minutes after going behind, with Liam Shepherd forced to clear off his line to deny Matty Blair.
From there on in it was nip and tuck, but Newport hung on to take the points.