The Terras were relegated as the Dragons eventually fired, scoring six in Dorset to nail their hosts’ coffin.
Tom Bearwish put Weymouth in front but the second half was a different story.
Jordan Davies and Paul Mullin, pictured, both scored twice with Ollie Palmer and James Jones also on target.
County’s lead is now four points - and the two sides face off next weekend.
King’s Lynn Town stay afloat thanks to Byron Webster’s leveller for Bromley against Aldershot Town, 1-1 it ended.
Dover have been down for some time and Notts County eventually got going at the Crabble.
Second half goals from Ed Francis, Callum Roberts and Ruben Rodrigues made the ten men pay.
Southend United fans have high hopes for next season and a 1-0 win over Boreham Wood kept the good feeling going. The winner was scored by Jack Bridge 13 minutes from time.
In the National League North, Alfreton Town are now eight unbeaten.
A 4-2 win over Curzon Ashton was sealed with a Matt Rhead double - it moved the Reds up to eighth.
York City ended their recent winless run with a big victory against former manager Steve Watson’s Chester. Lenell John-Lewis got the go to lift the Minstermen back into the play-off places.
In the only National League South game, a Mamadou Jobe strike cancelled out a Ben Harris opener as Concord Rangers and Slough Town drew 1-1.