Both teams cancelled each other out and Cornish fullback Adryan Winnan failed to open the scoring with an early missed penalty. Then after 24 minutes Mark Woodrow showed how it should be done to put Gloucestershire 3-0 ahead.
Cornwall took the lead minutes later when wing Sean Hawkey finished off a glorious Willem Dirksen break, Winnan adding the extras.
However, directly from the restart the Gloucestershire inside backs created space for Jake Carter to round the Cornish defence and score his first try. Woodrow converted and Gloucestershire regained the lead.
With half time looming a kick over the Cornish defence was gathered by Winnan. He returned the kick but the ball bounced away from the home cover into the grateful arms of lock Luke Collins who raced in for a try which Winnan converted.
Once again, Gloucestershire scored from the restart. The ball was moved into midfield where centres Jonny May and Dewi Scourfield once again created space. Crisp handling from second phase saw the ball moved to Carter who cut inside the cover for his second try. Woodrow converted and Gloucestershire went into the break 17-14 ahead.
The Gloucestershire forwards showed their superior fitness in the second half and the outstanding Matt Gilbert led a break out of defence three minutes after the restart.
Forwards and backs combined to pressurise the Cornish line and the ball was moved left for May to crash over for the third Gloucestershire try. Woodrow's conversion put them two scores ahead.
A try from Dirksen pegged Gloucestershire back but the home side were playing with great confidence and would have run in several further tries but for the good defence of the Cornish team.
Woodrow extended the lead with a penalty on 52 minutes immediately before Cornwall threw everything into attack. A magnificent double tackle on Cornwall No.8 Mark Bright by Woodrow and May stopped the New Zealander in his tracks and the ball was turned over. It was a crucial moment from which the visitors never recovered.
Carter completed his hat-trick following excellent attacking by May and Scourfield who were once more able to create space for the wing. Woodrow converted from wide out again to complete the scoring.
Mark Woodrow, the former Bristol outside half now plying his trade with Birmingham-Solihull had an outstanding match.
He kicked 14 points and was able to release his outside backs quickly and smoothly. He also gave a masterful display of tactical kicking punting long behind the Cornish defence and giving Gloucestershire valuable field position.
Scourfield and May in particular were a menace and Carter took his chances well. The pack as a unit played well with Mike Panoho and Matt Gilbert prominent in the loose.
Next Saturday Gloucestershire take on Lancashire in the County Championship Final at Twickenham. The game kicks off at midday and is a curtain raiser for the England v Barbarians match.
James Copsey (Cinderford); Chris Holder (Lydney), Jonny May (Hartpury Coll.), Dewi Scourfield (Cinderford), Jake Carter (Cinderford); Mark Woodrow (Birmingham & Solihull), Paul Knight (Cinderford) (Capt.); Paul Price (Lydney), Paul Finken (Newbury), Ricky Davies (Birmingham & Solihull), Will Waldron (Hartpury Coll), Royce Cadman (Hartpury Coll), Matt Gilbert (Hartpury Coll), Dean Jenkins (Lydney), Mike Panoho (Dings Crusaders).
Jimmy Williams (Lydney) for Knight, Chris McNeil (Cinderford) for Gilbert, Chris Hall (Cinderford) for Jenkins, Dave Bufton (Dings Crusaders) for Waldron
Gloucestershire - tries Jake Carter (3), Jonny May; conversions Mark Woodrow (4); penalties Woodrow (2)
Cornwall - tries Sean Hawkey, Luke Collins, Willem Dirksen; conversions Adryan Winnan (2)