Barnstaple and Wimbledon have both been relegated from National Two South while Old Redcliffians and London Irish Wild Geese survived the drop on the final day of the season.
Relegation for Barum and the Dons was confirmed after Old Redcliffians secured victory in their game against Redruth with Wild Geese clinching one point in a defeat to Worthing Raiders.
Wimbledon have lasted just one season at this level while Barnstaple's time in National Two South has come to an end after two terms.
Elsewhere on the final weekend of the campaign, Cinderford's party continued at home to Canterbury and Chinnor prepared for their play-off in style while Redingensians thrashed Henley Hawks, Taunton Titans edged past Broadstreet and Tonbridge Juddians fought back to beat Bury St Edmunds.
Cinderford 34-12 Canterbury
Cinderford celebrated promotion to National One with a comfortable triumph over Canterbury at Dockham Road to take their tally to 24 victories on the spin.
Harry Hone ran over twice for the Gloucestershire side and further tries from Reuben Norville, Nathan Taylor, Jimmy Williams and Roger Birkin saw Cinderford pull clear after a tight first half.
Canterbury's points came via Vaughan Meredith and Kieran Thompson.
Chinnor 52-14 Clifton
Chinnor prepared for their National Two play-off clash against Sedgley Park with a superb win over Clifton at Kingsey Road.
Jack Gilding, Tom Price, Ricky Cano and Luke Hibberd crossed to earn the hosts a bonus point just after half-time.
Dan Wells had gone over for Clifton just before break, but Chinnor added four more scores to their tally.
Josh Barton, Mike McDonald, Ben Manning and Jonny Bentley all scored as Chinnor surpassed 1000 points for this season while Elliot Booley crossed for Clifton.
Chinnor will now take on Sedgley Park for a place in National One on Saturday May 5th.
Redingensians 51-0 Henley Hawks
Redingensians recorded their biggest win of the campaign on the final day of the season as they ran in seven tries to beat Henley Hawks.
Ben Henderson, Connor Corrigan, Ellis Jones (2), Miles Lloyd, Joe Duffelen and Steve Bryant all crossed for the Berkshire club.
The Rams had already secured third place in the table, but rounded off a superb term with a stunning victory against a Henley side that will be disappointed to have won just one of their final 10 games. The Hawks ended the season in ninth place.
Broadstreet 21-26 Taunton Titans
Taunton Titans bounced back from last weekend's heavy defeat against Tonbridge Juddians with a victory over a spirited Broadstreet in the Midlands.
The visitors scored the opening try on 22 minutes through Ollie Rice, but James Moreton crossed for Broadstreet before Paul Davis' try saw the away side take a seven-point half-time lead.
Broadstreet scored a penalty try 15 minutes after the break, but Taunton responded as Lewis Webb darted over.
However, the already relegated hosts then went in front for the first time in this contest as Ed Boxhall crossed, but the Titans kept their cool to snatch the win as Rice grabbed his second late on.
Old Redcliffians 34-12 Redruth
Old Redcliffians ran in five tries as they beat Redruth to secure their survival in National Two South.
The hosts knew a victory would keep them in this division, regardless of results elsewhere and tries from Ethan Doyle (2), Kieran Ward, Scott Coster and Sam Smith secured safety for Saul Nelson's side.
Huge performance from the @OldRedsRFC boys today to beat Redruth and secure our Nat 2 South status! So proud of their achievement... UTR
— Saul Nelson (@SJNelson1980) April 28, 2018
Redruth did manage to trouble Old Reds' defence with Alex Ducker and Loma Kipivila both crossing, but after eight wins from 14 matches since Christmas, the men from Scotland Lane have beaten the drop.
Tonbridge Juddians 36-28 Bury St Edmunds
Tonbride Juddians signed off the season in style as they came from behind with 14-men to beat Bury St Edmunds at the Slade.
The Suffolk side led 14-10 in the first half, but they saw a likely victory snatched away from them in the final 10 minutes of this contest.
Finlay Coxon-Smith, Ryan Jackson, George Lawson, Mike O'Sullivan and Reece Conlon got the TJ's tries, despite seeing Sam Atiola red-carded just after half-time.
Sean Stapleton, Craig Wilson, Dwayne Corcoran and Mark Kohler crossed for the home side who had led 21-10 at one stage in this contest.
London Irish Wild Geese 19-26 Worthing Raiders
London Irish Wild Geese will be playing in National Two South next season as Jack Cooke's late try secured them their survival despite losing to Worthing Raiders.
Lee Starling's side required just one point from this fixture at Hazlewood to avoid the drop.
— London Irish Wild Geese (@GeeseRugby) April 28, 2018
The Geese had led this contest at the break thanks to a brace from Bradley Clements while Harrison Sims replied for Worthing.
The visitors were much better after the break as a score from Joe Spurgeon and a double from David McIlwaine gave the Raiders the lead which they never relinquished, but the vital moment in the game came two minutes from the end as Cooke dotted down to confirm London Irish Wild Geese's safety.
Barnstaple 17-14 Wimbledon
Both Barnstaple and Wimbledon have been relegated from National Two South after Old Redcliffians' win over Redruth at Scotland Lane.
Barum and the Dons needed Redruth to do them a favour in Bristol if either side had any chance of staying up, but Old Reds' victory sealed their fate.
Well Nat 2 we've had a blast these past two seasons and made some great new friends. Further reflection tomorrow BUT we will be back! ??????
— BarnstapleRFC (@BarnstapleRFC) April 28, 2018
James Doe's converted try gave Wimbledon a 7-0 half-time lead.
After the break, Niall McSweeney doubled the Dons' advantage, but tries from Kyle Spear and Danny Southworth levelled the game.
Barnstaple then struck a penalty to seal the victory, but it unfortunately, it was in vain.