Saxons became the only team to win home and away against Lewes this season - a side that had only conceded seven goals in its previous 15 games.
Three goals up inside 10 frenetic minutes, the hosts set the scene for a memorable victory at Horntye Park.
Man-of-the-match Isaac Wall, stepping up from the Warriors, capped a fine display grabbing the first when he latched on to Buckner's far post pile-driver.
Winger Tony Wright then slipped into the D and smashed the ball home from close range before Buckner made it 3-0 from a short corner.
The second half was one-way traffic as Saxons poured forward led by the inspirational midfield duo of Rak Patel and Ben Simmonds.
Buckner secured a hat-trick, Joe Woodford scored twice, Wright grabbed a second, Brock Smith converted a penalty and Simmonds scored to make it the perfect 10.
Buckner said: "I told the lads I was speechless at half-time when it was 3-0.
"And then we went and scored another seven in the second half. I'm still pinching myself and am so proud of what we have achieved this season. We've worked so hard and trained hard and it's all paying off. I ask for 100 per cent effort and on Saturday the lads gave me 110 per cent. An unforgettable result."
Fourth-placed Saxons travel to third placed Brighton tomorrow (SAT) to face the club's sixth team.
Team: Heath (GK) Acott, Wall, Cornish, Smith, Patel, Simmonds, Wright, Buckner (C), Klein, Woodford, Orr, Binodh
Man-of-match: Wall