For Gloucestershire they missed the chance to win back the title for the first time in seven years, as well as equal Lancashire's previous record haul of 18 titles.
Lancashire, who were last in the final in 2007, made a sizzling start in the sunshine, putting down their marker early on with a try after just six minutes.
The score came following some good early pressure, and with centre Mathew Riley making a good break Lancashire powered up field through several phases of play. Flanker Crous then found some space and scored. Fly half Alex Davies missed the conversion.
Gloucestershire immediately bounced back though with a superb try. After a scrum, centre Dewi Scourfield made a good break. Fly half Mark Woodrow then executed a clever chip up field on the left wing, which Lydney winger Chris Holder collected and then dived over the try line. With Woodrow missing the conversion both sides were tied 5-5 after ten minutes.
Lancashire edged ahead with three penalties, including one on the stroke of half-time and with Gloucestershire only converting two out of three penalty attempts they trailed their rivals 11-14 at the break.
Gloucestershire continued to be punished for their ill discipline after the restart with Lancashire being handed two penalties. Fly half Davies could only convert one of his attempts, much to the West Country men's relief.
A great break by Hartpury College's Jonny May down the left wing then saw Gloucestershire go ahead for the first time in the game after 50 minutes. His superb run, and the chip in field, saw Lancashire fail to collect the ball and instead flanker Dean Jenkins ran in to touch down for an opportunist try. With Woodrow converting Gloucestershire took an 18-17 lead.
But Gloucestershire's lead was short-lived, and when Fylde's Royle found some space on the right wing, he cruised his way through Gloucestershire's defence to show a tremendous turn of pace and score in the corner. Davies missed the conversion leaving Lancashire with a four point cushion.
Lancashire then edged into a 25-18 lead with 20 minutes remaining after Davies nudged over another penalty before a tremendous break by Riley put the game out of reach for Gloucestershire.
The Sedgley Tigers back ran in from nearly 40 metres out and despite Gloucestershire's best efforts to bring Riley down they couldn't and he muscled his way over the line and under the posts. With Davies adding the conversion with ten minutes remaining they had done enough to secure the title.
Lancashire captain Stephen Nutt said: "This is a tremendous achievement. The players have really bought into the ethos of county rugby and gelled together so quickly this season. We knew we had the firing power in all departments and today we performed. The forwards really took control of the game, and our defence was really solid. We have won the cup and we are absolutely delighted."
Paul Williams, Gloucestershire's backs coach, added: "We are obviously very disappointed. They dominated the contact area well, and we lost a lot of possession and when you lose that much it is always going to go against you.
We thought that we would get stronger as the game went on but you have to give Lancashire credit for coming back after we took the lead. They showed their fitness and the will to win."
15 James Copsey (Cinderford), 14 Chris Holder (Lydney), 13 Jonny May (Hartpury College), 12 Dewi Scourfield (Cinderford), 11 Jaike Carter (Cinderford), 10 Mark Woodrow (Cinderford), 9 Paul Knight (Cinderford) C, 1 Paul Price (Lydney), 2 Paul Finken (Newbury), 3 Ricky Davies (Birmingham & Solihull), 4 Will Waldron (Hartpury College), 5 Royce Cadman (Hartpury College), 6 Mathew Gilbert (Hartpury College), 7 Dean Jenkins (Lydney), 8 Mike Panoho (Dings Crusaders).
16 Chris Hall (Cinderford), 17 Matt Long (Birmingham & Solihull), 18 Dave Bufton (Dings Crusaders), 19 Tim Stevenson (Cinderford), 20 Jimmy Williams (Lydney) 21 Chris McNeil (Cinderford), 22 Sylvan Edwards (Dings Crusaders)
Tries: Holder, Jenkins
Penalties: Woodrow (2)
15 Stephen Nutt (Capt) (Fylde), 14 Nicholas Royle (Fylde), 13 Mark Turner (Caldy), 12 Matthew Riley (Sedgley Tigers), 11 Oliver Brennand (Fylde), 10 Alex Davies (Plymouth Albion), 9 Ryan de La Harpe (West Park), 1 Robert O'Donnell (Manchester), 2 David Ward (Manchester), 3 Petrus Du Plessis (Sedgley Tigers), 4 Louis McGowan (Rotherham Titans), 5 Sam Beaumont (Fylde), 6 Juan Crous (Sedgley Tigers), 7 Daniel Baines (Macclesfield), 8 Sebastian Moss (Manchester).
16 Kieran Brookes (Fylde), 17 Charlie Baleirara (West Park), 18 Andrew Dockray (Preston Grasshoppers), 19 Garth Dew (Manchester), 20 Matthew Williams (Waterloo), 21 Tom Barlow (Rotherham Titans), 22 Craig Aikman Fylde. Travelling Reserves: 23 Russell Flynn (Preston Grasshoppers), 24 Steve Collins (Rochdale).
Tries: Crous, Royle, Riley
Penalties: Davies 5
Half-time score: Gloucestershire 11 Lancashire 14