Ian Jones’ men won 21 of their 22 league matches with a 28-15 home defeat by Nant back on January 21 the only blot on their copybook.
In a season where they reached the quarter-finals of the WRU National Plate, Pwllheli rounded off a superb campaign by beating Bala to also win the North Wales Cup.
On his side’s success, head coach Jones said: “We’re very proud to have won the league and it’s a big achievement for the boys.
“It’s been a good end to the season; that’s three titles back-to-back – and the cup was the icing on the cake. It was neck and neck with Nant as it always is.
“We’ve played them three times this year in league and cup and beaten them twice. There’s an intense rivalry. They are a very good side and worthy opponents – as are Bala and Caernarfon. The challenge for us is to keep it going, as you’re there to be taken.”
On his highlights of the season, Jones picked out the 29-20 win at Division One West outfit Llanelli Wanderers in round three of the Plate back on December 10, as well as their 71-0 win at Mold in the final league game on May 6.
He said: “On paper our best result was against Llanelli Wanderers who are a very good side. But, apart from that, the best game we put together was the last one against Mold, because they’re not a bad side, we just clicked and our tempo was excellent.”
