Carmarthen Quins and Blackwood won SWALEC League Division One West and East respectively - with Quins clinching promotion to the Principality Premiership.
The Carmarthen Park club would have had to face off with their Gwent opponents in an end-of-season promotional play-off had it not been for stadium issues.
As Blackwood's Glan-Y-Afon ground does not meet the WRU's Premiership standards, Quins bypass any prospective play-off and go straight into the top division.
To make matters sweeter for Quins, they clinched the title at town rivals Carmarthen Athletic, thanks to a narrow 17-15 win at Five Fields.
In an end-to-end match where the lead regularly changed hands, Quins scrum-half Ricky Richards went over to effectively earn the visitors the title.
Quins treasurer Alan Jones lavished praise on the title winning team, but vowed they were not finished yet. He said: "It has been a team effort with all our squad playing their part.
"We have won all our league games this season and are now aiming to win the remaining two games. We have never gone through a season unbeaten, so we are keen to win 22 from 22."
Next week they host second place Tonmawr, who look in good shape to deny them this honour after they thrashed Maesteg 55-0, scoring nine tries.
In the East, Blackwood were presented with the title in front of their own fans after their match with Bargoed. Gareth Risby-Davies, with two, Gavin Rees and David Brake were the Blackwood try scorers in a comfortable 32-21 win.
Despite being denied promotion, nothing was dampening spirits at Glan-Y-Afon. Team manager Craig Clements said: "We had a two-year plan for our young squad, and achieved our goal within this time. We are now hoping for the club to push on next year and win the league title again."
Carmarthen Quins are holding an exhibition to commemorate club players who fought in World War I. All welcome to the clubhouse on Friday afternoon to learn more about local history, or share any family anecdotes or artifacts.