Douglas’ second string gained revenge for last season’s final defeat by clinching the Manx Plate on Saturday.
A year after losing the showpiece to Vagabonds B, they turned the tables on their old rivals with an 18-16 victory.
After Douglas took an early lead with a Charlie Henthorn try, Vagas hit back via three Johnny Beckley penalties to lead 9-5 at half-time.
The first 25 minutes of the second half were scoreless but with 15, Douglas made their move.
Sam Peel kicked a penalty to get them to within a point.
Alex Cain made the most of a defensive error to give Douglas the lead and when Conor McCaughan was driven over from close range, Douglas were 18-9 in front and cruising.
A late try and conversion from Beckley brought Vagas back to within two but with insufficient time to retake the lead.
Emerging Nomads finished their season on a high with a 24-21 win over Ramsey B.
The winning margin was not enough to give them a place in the final of the Shimmin Wilson Manx Bowl which will be between Ramsey B and Castletown.
Conor Stephens and Vaughan Paddock both picked up a brace for Nomads, with Will Cain adding two conversions.
Daniel Webb, Gareth Hinge and James Wren all crossed for Ramsey with Wren converting three.