Leith edged out St Boswells in the Borders on Saturday to confirm them as RBS East Three champions.
The Academy Park side travelled down to their final league match of the season with one hand on the trophy after Inverleith slipped up last midweek against Broughton.
And they recorded a 10-3 win over the side who will finish third to spark celebrations among the players after a long, hard season.
In East One, one of the most bizarre results of the season was posted at Cavalry Park with Portobello beating already crowned champions and national Shield runners-up Livingston 118-0.
Livingston filled their team with mainly second XV and young players after their tough loss to Marr the previous week at Murrayfield.
Hamish Munro led the way for Porty with 38 points while Rob Ritchie ran in four tries and the likes of Cammy Walker, Chris Sinclair and Chris Thomas all ran in two tries each. The win meant that Porty finished fifth.
Hawick Linden defeated Earlston to clinch the East Two title while, on Friday, Gala YM were thrown out of the league for not fulfilling fixtures on four separate occasions.
On the Kings of the Sevens circuit, Edinburgh Accies are now third in the overall table after they reached the Langholm Sevens final on Saturday.
They won through the first round before beating Melrose and Gala on the way to a final defeat by Selkirk.