A Rhys Hart hat-trick and a strike by Cadan Grahame saw them crowned champions ahead of PGSOB’s B team, who took second after hammering Bude 8-2.
Caradon were third, two points behind PGSOB and five behind Marjon’s C.
However, there was double disappointment for Marjon’s B team, who lost out on promotion from Southern One and missed out on a place in the Devon Cup final after two defeats within the space of 24 hours at the hands of Teign Hockey Club.
Teign had already guaranteed themselves the Southern One title but the league’s second spot was up for grabs.
Marjon went into the final weekend two points ahead of Darts, but their Devon rivals ended the weekend one point ahead after they beat Okehampton 8-2 and Plymouth lost 5-0 at champions Teign.
Teign dominated against Marjon B and debutant and man-of-the-match Derrick Brown put the home side ahead after a Tom Brooks assist.
Brown then notched a second after good work by Dave Eaton-Jones.
Teign went in at half-time 3-0 up after George Burningham half-volleyed an aerial ball from Rich Fisher.
After the interval Josh Boyne flicked into the top right corner from a short corner before Burningham added a fifth.
The Devon Cup match the following day was a lot tighter, with both sides making team changes.
The tie ended up going to penalty flicks after finishing 1-1 and Teign narrowly won the shoot-out 4-3 to book a place in the final against ISCA A at Exeter University on April 11.
Marjon had gone 1-0 up after they won a penalty flick from a well-worked short corner. Teign goalkeeper and joint man-of-the-match Oli Robinson managed to get a stick to the ball but he was unable to keep Marjon captain and former Wales international Clive O’Sullivan’s flick out.
It looked like O’Sullivan’s penalty might be enough to win the semi-final but with just 90 seconds left South African and joint man-of-the-match Richie Fisher levelled the tie and took it to a shoot-out with a thunderous shot from a short corner.
Fisher, Simon Dallas, Josh Boyne and captain Jacob O’Connor all scored penalties for Teign before Robinson sensationally saved with his helmet to secure his team a final place.
Elsewhere, there was disappointment for PGSOBs in Conference South.
Although they beat Marjon A 2-0 away, they lost out on second spot behind champions Ashmoor by virtue of goal difference, with Bridgwater taking the runners-up place after beating ECV Hornets A 6-0. That was enough for them to finish with goal difference of plus-35 compared to PGSOB’s 33.
Marjon A finished the season in fourth spot in that division.
Marjon’s first team finished seventh in the Premiership. Their campaign ended with a 5-4 away defeat at Cheltenham A.