Ebbw Vale won the Division One East title at Bedlinog on the 23 April but the Steelmen left it late.
Ebbw needed to win with a bonus point to leapfrog Newbridge courtesy of having won more games over the course of the season.
They did just that but only in the closing stages when their hosts collapsed a scrum on their line.
That was the Steelmen's fourth score after earlier efforts by back row Ethan Matthews, prolific prop Ross Jones and powerful wing Danny Ajuwa.
The five-point haul means that Ebbw win the title and enter the promotion/relegation play-offs with Premiership basement dwellers Glamorgan Wanderers their opponents next Saturday.